Chapter 4 Practice Problems (Practice – no credit) Due: 11:59pm on Friday, February 14, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Advice for the Quarterback A quarterback is set up to throw the football to a receiver who is running with a constant velocity directly away from the quarterback and is now a distance away from the quarterback. The quarterback figures that the ball must be thrown at an angle to the horizontal and he estimates that the receiver must catch the ball a time interval after it is thrown to avoid having opposition players prevent the receiver from making the catch. In the following you may assume that the ball is thrown and caught at the same height above the level playing field. Assume that the y coordinate of the ball at the instant it is thrown or caught is and that the horizontal position of the quaterback is . Use for the magnitude of the acceleration due to gravity, and use the pictured inertial coordinate system when solving the problem. Part A Find , the vertical component of the velocity of the ball when the quarterback releases it. Express in terms of and . Hint 1. Equation of motion in y direction What is the expression for , the height of the ball as a function of time? Answer in terms of , , and . v r D  tc y = 0 x = 0 g v0y v0y tc g y(t) t g v0y ANSWER: Incorrect; Try Again Hint 2. Height at which the ball is caught, Remember that after time the ball was caught at the same height as it had been released. That is, . ANSWER: Answer Requested Part B Find , the initial horizontal component of velocity of the ball. Express your answer for in terms of , , and . Hint 1. Receiver’s position Find , the receiver’s position before he catches the ball. Answer in terms of , , and . ANSWER: Football’s position y(t) = v0yt− g 1 2 t2 y(tc) tc y(tc) = y0 = 0 v0y = gtc 2 v0x v0x D tc vr xr D vr tc xr = D + vrtc Typesetting math: 100% Find , the horizontal distance that the ball travels before reaching the receiver. Answer in terms of and . ANSWER: ANSWER: Answer Requested Part C Find the speed with which the quarterback must throw the ball. Answer in terms of , , , and . Hint 1. How to approach the problem Remember that velocity is a vector; from solving Parts A and B you have the two components, from which you can find the magnitude of this vector. ANSWER: Answer Requested Part D xc v0x tc xc = v0xtc v0x = + D tc vr v0 D tc vr g v0 = ( + ) + D tc vr 2 ( ) gtc 2 2 −−−−−−−−−−−−−−−−−−−  Typesetting math: 100% Assuming that the quarterback throws the ball with speed , find the angle above the horizontal at which he should throw it. Your solution should contain an inverse trig function (entered as asin, acos, or atan). Give your answer in terms of already known quantities, , , and . Hint 1. Find angle from and Think of velocity as a vector with Cartesian coordinates and . Find the angle that this vector would make with the x axis using the results of Parts A and B. ANSWER: Answer Requested Direction of Velocity at Various Times in Flight for Projectile Motion Conceptual Question For each of the motions described below, determine the algebraic sign (positive, negative, or zero) of the x component and y component of velocity of the object at the time specified. For all of the motions, the positive x axis points to the right and the positive y axis points upward. Alex, a mountaineer, must leap across a wide crevasse. The other side of the crevasse is below the point from which he leaps, as shown in the figure. Alex leaps horizontally and successfully makes the jump. v0  v0x v0y v0  v0x v0y v0xx^ v0yy^   = atan( ) v0y v0x Typesetting math: 100% Part A Determine the algebraic sign of Alex’s x velocity and y velocity at the instant he leaves the ground at the beginning of the jump. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Typesetting math: 100% Hint 1. Algebraic sign of velocity The algebraic sign of the velocity is determined solely by comparing the direction in which the object is moving with the direction that is defined to be positive. In this example, to the right is defined to be the positive x direction and upward the positive y direction. Therefore, any object moving to the right, whether speeding up, slowing down, or even simultaneously moving upward or downward, has a positive x velocity. Similarly, if the object is moving downward, regardless of any other aspect of its motion, its y velocity is negative. Hint 2. Sketch Alex’s initial velocity On the diagram below, sketch the vector representing Alex’s velocity the instant after he leaves the ground at the beginning of the jump. ANSWER: ANSWER: Typesetting math: 100% Answer Requested Part B Determine the algebraic signs of Alex’s x velocity and y velocity the instant before he lands at the end of the jump. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Typesetting math: 100% Hint 1. Sketch Alex’s final velocity On the diagram below, sketch the vector representing Alex’s velocity the instant before he safely lands on the other side of the crevasse. ANSWER: Answer Requested ANSWER: Answer Requested Typesetting math: 100% At the buzzer, a basketball player shoots a desperation shot. The ball goes in! Part C Determine the algebraic signs of the ball’s x velocity and y velocity the instant after it leaves the player’s hands. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Hint 1. Sketch the basketball’s initial velocity On the diagram below, sketch the vector representing the velocity of the basketball the instant after it leaves the player’s hands. ANSWER: Typesetting math: 100% ANSWER: Correct Part D Determine the algebraic signs of the ball’s x velocity and y velocity at the ball’s maximum height. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Hint 1. Sketch the basketball’s velocity at maximum height Typesetting math: 100% On the diagram below, sketch the vector representing the velocity of the basketball the instant it reaches its maximum height. ANSWER: ANSWER: Answer Requested PSS 4.1 Projectile Motion Problems Learning Goal: Typesetting math: 100% To practice Problem-Solving Strategy 4.1 for projectile motion problems. A rock thrown with speed 9.00 and launch angle 30.0 (above the horizontal) travels a horizontal distance of = 17.0 before hitting the ground. From what height was the rock thrown? Use the value = 9.810 for the free-fall acceleration. PROBLEM-SOLVING STRATEGY 4.1 Projectile motion problems MODEL: Make simplifying assumptions, such as treating the object as a particle. Is it reasonable to ignore air resistance? VISUALIZE: Use a pictorial representation. Establish a coordinate system with the x axis horizontal and the y axis vertical. Show important points in the motion on a sketch. Define symbols, and identify what you are trying to find. SOLVE: The acceleration is known: and . Thus, the problem becomes one of two-dimensional kinematics. The kinematic equations are , . is the same for the horizontal and vertical components of the motion. Find from one component, and then use that value for the other component. ASSESS: Check that your result has the correct units, is reasonable, and answers the question. Model Start by making simplifying assumptions: Model the rock as a particle in free fall. You can ignore air resistance because the rock is a relatively heavy object moving relatively slowly. Visualize Part A Which diagram represents an accurate sketch of the rock’s trajectory? Hint 1. The launch angle In a projectile’s motion, the angle of the initial velocity above the horizontal is called the launch angle. ANSWER: m/s  d m g m/s2 ax = 0 ay = −g xf = xi +vixt, yf = yi +viyt− g(t 1 2 )2 vfx = vix = constant, and vfy = viy − gt t t v i Typesetting math: 100% Typesetting math: 100% Correct Part B As stated in the strategy, choose a coordinate system where the x axis is horizontal and the y axis is vertical. Note that in the strategy, the y component of the projectile’s acceleration, , is taken to be negative. This implies that the positive y axis is upward. Use the same convention for your y axis, and take the positive x axis to be to the right. Where you choose your origin doesn’t change the answer to the question, but choosing an origin can make a problem easier to solve (even if only a bit). Usually it is nice if the majority of the quantities you are given and the quantity you are trying to solve for take positive values relative to your chosen origin. Given this goal, what location for the origin of the coordinate system would make this problem easiest? ANSWER: ay At ground level below the point where the rock is launched At the point where the rock strikes the ground At the peak of the trajectory At the point where the rock is released At ground level below the peak of the trajectory Typesetting math: 100% Correct It’s best to place the origin of the coordinate system at ground level below the launching point because in this way all the points of interest (the launching point and the landing point) will have positive coordinates. (Based on your experience, you know that it’s generally easier to work with positive coordinates.) Keep in mind, however, that this is an arbitrary choice. The correct solution of the problem will not depend on the location of the origin of your coordinate system. Now, define symbols representing initial and final position, velocity, and time. Your target variable is , the initial y coordinate of the rock. Your pictorial representation should be complete now, and similar to the picture below: Solve Part C Find the height from which the rock was launched. Express your answer in meters to three significant figures. yi yi Typesetting math: 100% Hint 1. How to approach the problem The time needed to move horizontally to the final position = 17.0 is the same time needed for the rock to rise from the initial position to the peak of its trajectory and then fall to the ground. Use the information you have about motion in the horizontal direction to solve for . Knowing this time will allow you to use the equations of motion for the vertical direction to solve for . Hint 2. Find the time spent in the air How long ( ) is the rock in the air? Express your answer in seconds to three significant figures. Hint 1. Determine which equation to use Which of the equations given in the strategy and shown below is the most appropriate to calculate the time the rock spent in the air? ANSWER: Hint 2. Find the x component of the initial velocity What is the x component of the rock’s initial velocity? Express your answer in meters per second to three significant figures. ANSWER: ANSWER: t xf = d m yi t yi t t xf = xi + vixt yf = yi + viyt− g(t 1 2 )2 vfy = viy − gt vix = 7.79 m/s Typesetting math: 100% Hint 3. Find the y component of the initial velocity What is the y component of the rock’s initial velocity? Express your answer in meters per second to three significant figures. ANSWER: ANSWER: Answer Requested Assess Part D A second rock is thrown straight upward with a speed 4.500 . If this rock takes 2.181 to fall to the ground, from what height was it released? Express your answer in meters to three significant figures. Hint 1. Identify the known variables What are the values of , , , and for the second rock? Take the positive y axis to be upward and the origin to be located on the ground where the rock lands. Express your answers to four significant figures in the units shown to the right, separated by commas. ANSWER: t = 2.18 s viy = 4.50 m/s yi = 13.5 m m/s s H yf viy t a Typesetting math: 100% Answer Requested Hint 2. Determine which equation to use to find the height Which equation should you use to find ? Keep in mind that if the positive y axis is upward and the origin is located on the ground, . ANSWER: ANSWER: Answer Requested Projectile motion is made up of two independent motions: uniform motion at constant velocity in the horizontal direction and free-fall motion in the vertical direction. Because both rocks were thrown with the same initial vertical velocity, 4.500 , and fell the same vertical distance of 13.5 , they were in the air for the same amount of time. This result was expected and helps to confirm that you did the calculation in Part C correctly. ± Arrow Hits Apple An arrow is shot at an angle of above the horizontal. The arrow hits a tree a horizontal distance away, at the same height above the ground as it was shot. Use for the magnitude of the acceleration due to gravity. Part A , , , = 0,4.500,2.181,-yf viy t a 9.810 m, m/s, s, m/s2 H yi = H yf = yi + viyt− g(t 1 2 )2 vfy = viy − gt = − 2g( − ) v2f y v2i y yf yi H = 13.5 m viy = m/s m  = 45 D = 220 m g = 9.8 m/s2 Typesetting math: 100% Find , the time that the arrow spends in the air. Answer numerically in seconds, to two significant figures. Hint 1. Find the initial upward component of velocity in terms of D. Introduce the (unknown) variables and for the initial components of velocity. Then use kinematics to relate them and solve for . What is the vertical component of the initial velocity? Express your answer symbolically in terms of and . Hint 1. Find Find the horizontal component of the initial velocity. Express your answer symbolically in terms of and given symbolic quantities. ANSWER: Hint 2. Find What is the vertical component of the initial velocity? Express your answer symbolically in terms of . ANSWER: ANSWER: ta vy0 vx0 ta vy0 ta D vx0 vx0 ta vx0 = D ta vy0 vy0 vx0 vy0 = vx0 vy0 = D ta Typesetting math: 100% Hint 2. Find the time of flight in terms of the initial vertical component of velocity. From the change in the vertical component of velocity, you should be able to find in terms of and . Give your answer in terms of and . Hint 1. Find When applied to the y-component of velocity, in this problem the formula for with constant acceleration is What is , the vertical component of velocity when the arrow hits the tree? Answer symbolically in terms of only. ANSWER: ANSWER: Hint 3. Put the algebra together to find symbolically. If you have an expression for the initial vertical velocity component in terms in terms of and , and another in terms of and , you should be able to eliminate this initial component to find an expression for Express your answer symbolically in terms of given variables. ANSWER: ta vy0 g vy0 g vy(ta) v(t) −g vy(t) = vy0 − g t vy(ta ) vy0 vy(ta) = −vy0 ta = 2vy0 g ta D ta g ta ta2 t2 = a 2D g Typesetting math: 100% ANSWER: Answer Requested Suppose someone drops an apple from a vertical distance of 6.0 meters, directly above the point where the arrow hits the tree. Part B How long after the arrow was shot should the apple be dropped, in order for the arrow to pierce the apple as the arrow hits the tree? Express your answer numerically in seconds, to two significant figures. Hint 1. When should the apple be dropped The apple should be dropped at the time equal to the total time it takes the arrow to reach the tree minus the time it takes the apple to fall 6.0 meters. Hint 2. Find the time it takes for the apple to fall 6.0 meters How long does it take an apple to fall 6.0 meters? Express your answer numerically in seconds, to two significant figures. ANSWER: Answer Requested ANSWER: ta = 6.7 s tf = 1.1 s td = 5.6 s Typesetting math: 100% Answer Requested Video Tutor: Ball Fired Upward from Accelerating Cart First, launch the video below. You will be asked to use your knowledge of physics to predict the outcome of an experiment. Then, close the video window and answer the questions at right. You can watch the video again at any point. Part A Consider the video you just watched. Suppose we replace the original launcher with one that fires the ball upward at twice the speed. We make no other changes. How far behind the cart will the ball land, compared to the distance in the original experiment? Hint 1. Determine how long the ball is in the air How will doubling the initial upward speed of the ball change the time the ball spends in the air? A kinematic equation may be helpful here. The time in the air will ANSWER: be cut in half. stay the same. double. quadruple. Typesetting math: 100% Hint 2. Determine the appropriate kinematic expression Which of the following kinematic equations correctly describes the horizontal distance between the ball and the cart at the moment the ball lands? The cart’s initial horizontal velocity is , its horizontal acceleration is , and is the time elapsed between launch and impact. ANSWER: ANSWER: Correct The ball will spend twice as much time in the air ( , where is the ball’s initial upward velocity), so it will land four times farther behind the cart: (where is the cart’s horizontal acceleration). Video Tutor: Ball Fired Upward from Moving Cart First, launch the video below. You will be asked to use your knowledge of physics to predict the outcome of an experiment. Then, close the video window and answer the questions at right. You can watch the video again at any point. d v0x ax t d = v0x t d = 1 2 axv0x t2 d = v0x t+ 1 2 axt2 d = 1 2 axt2 the same distance twice as far half as far four times as far by a factor not listed above t = 2v0y/g v0y d = 1 2 axt2 ax Typesetting math: 100% Part A The crew of a cargo plane wishes to drop a crate of supplies on a target below. To hit the target, when should the crew drop the crate? Ignore air resistance. Hint 1. How to approach the problem While the crate is on the plane, it shares the plane’s velocity. What is the crate’s velocity immediately after it is released? Hint 2. What affects the motion of the crate? Gravity will accelerate the crate downward. What, if anything, affects the crate’s horizontal motion? (Keep in mind that we are told to ignore air resistance, even though that’s not very realistic in this situation.) ANSWER: Correct At the moment it is released, the crate shares the plane’s horizontal velocity. In the absence of air resistance, the crate would remain directly below the plane as it fell. Score Summary: Your score on this assignment is 0%. Before the plane is directly over the target After the plane has flown over the target When the plane is directly over the target Typesetting math: 100% You received 0 out of a possible total of 0 points. Typesetting math: 100%

Chapter 4 Practice Problems (Practice – no credit) Due: 11:59pm on Friday, February 14, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Advice for the Quarterback A quarterback is set up to throw the football to a receiver who is running with a constant velocity directly away from the quarterback and is now a distance away from the quarterback. The quarterback figures that the ball must be thrown at an angle to the horizontal and he estimates that the receiver must catch the ball a time interval after it is thrown to avoid having opposition players prevent the receiver from making the catch. In the following you may assume that the ball is thrown and caught at the same height above the level playing field. Assume that the y coordinate of the ball at the instant it is thrown or caught is and that the horizontal position of the quaterback is . Use for the magnitude of the acceleration due to gravity, and use the pictured inertial coordinate system when solving the problem. Part A Find , the vertical component of the velocity of the ball when the quarterback releases it. Express in terms of and . Hint 1. Equation of motion in y direction What is the expression for , the height of the ball as a function of time? Answer in terms of , , and . v r D  tc y = 0 x = 0 g v0y v0y tc g y(t) t g v0y ANSWER: Incorrect; Try Again Hint 2. Height at which the ball is caught, Remember that after time the ball was caught at the same height as it had been released. That is, . ANSWER: Answer Requested Part B Find , the initial horizontal component of velocity of the ball. Express your answer for in terms of , , and . Hint 1. Receiver’s position Find , the receiver’s position before he catches the ball. Answer in terms of , , and . ANSWER: Football’s position y(t) = v0yt− g 1 2 t2 y(tc) tc y(tc) = y0 = 0 v0y = gtc 2 v0x v0x D tc vr xr D vr tc xr = D + vrtc Typesetting math: 100% Find , the horizontal distance that the ball travels before reaching the receiver. Answer in terms of and . ANSWER: ANSWER: Answer Requested Part C Find the speed with which the quarterback must throw the ball. Answer in terms of , , , and . Hint 1. How to approach the problem Remember that velocity is a vector; from solving Parts A and B you have the two components, from which you can find the magnitude of this vector. ANSWER: Answer Requested Part D xc v0x tc xc = v0xtc v0x = + D tc vr v0 D tc vr g v0 = ( + ) + D tc vr 2 ( ) gtc 2 2 −−−−−−−−−−−−−−−−−−−  Typesetting math: 100% Assuming that the quarterback throws the ball with speed , find the angle above the horizontal at which he should throw it. Your solution should contain an inverse trig function (entered as asin, acos, or atan). Give your answer in terms of already known quantities, , , and . Hint 1. Find angle from and Think of velocity as a vector with Cartesian coordinates and . Find the angle that this vector would make with the x axis using the results of Parts A and B. ANSWER: Answer Requested Direction of Velocity at Various Times in Flight for Projectile Motion Conceptual Question For each of the motions described below, determine the algebraic sign (positive, negative, or zero) of the x component and y component of velocity of the object at the time specified. For all of the motions, the positive x axis points to the right and the positive y axis points upward. Alex, a mountaineer, must leap across a wide crevasse. The other side of the crevasse is below the point from which he leaps, as shown in the figure. Alex leaps horizontally and successfully makes the jump. v0  v0x v0y v0  v0x v0y v0xx^ v0yy^   = atan( ) v0y v0x Typesetting math: 100% Part A Determine the algebraic sign of Alex’s x velocity and y velocity at the instant he leaves the ground at the beginning of the jump. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Typesetting math: 100% Hint 1. Algebraic sign of velocity The algebraic sign of the velocity is determined solely by comparing the direction in which the object is moving with the direction that is defined to be positive. In this example, to the right is defined to be the positive x direction and upward the positive y direction. Therefore, any object moving to the right, whether speeding up, slowing down, or even simultaneously moving upward or downward, has a positive x velocity. Similarly, if the object is moving downward, regardless of any other aspect of its motion, its y velocity is negative. Hint 2. Sketch Alex’s initial velocity On the diagram below, sketch the vector representing Alex’s velocity the instant after he leaves the ground at the beginning of the jump. ANSWER: ANSWER: Typesetting math: 100% Answer Requested Part B Determine the algebraic signs of Alex’s x velocity and y velocity the instant before he lands at the end of the jump. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Typesetting math: 100% Hint 1. Sketch Alex’s final velocity On the diagram below, sketch the vector representing Alex’s velocity the instant before he safely lands on the other side of the crevasse. ANSWER: Answer Requested ANSWER: Answer Requested Typesetting math: 100% At the buzzer, a basketball player shoots a desperation shot. The ball goes in! Part C Determine the algebraic signs of the ball’s x velocity and y velocity the instant after it leaves the player’s hands. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Hint 1. Sketch the basketball’s initial velocity On the diagram below, sketch the vector representing the velocity of the basketball the instant after it leaves the player’s hands. ANSWER: Typesetting math: 100% ANSWER: Correct Part D Determine the algebraic signs of the ball’s x velocity and y velocity at the ball’s maximum height. Type the algebraic signs of the x velocity and the y velocity separated by a comma (examples: +,- and 0,+). Hint 1. Sketch the basketball’s velocity at maximum height Typesetting math: 100% On the diagram below, sketch the vector representing the velocity of the basketball the instant it reaches its maximum height. ANSWER: ANSWER: Answer Requested PSS 4.1 Projectile Motion Problems Learning Goal: Typesetting math: 100% To practice Problem-Solving Strategy 4.1 for projectile motion problems. A rock thrown with speed 9.00 and launch angle 30.0 (above the horizontal) travels a horizontal distance of = 17.0 before hitting the ground. From what height was the rock thrown? Use the value = 9.810 for the free-fall acceleration. PROBLEM-SOLVING STRATEGY 4.1 Projectile motion problems MODEL: Make simplifying assumptions, such as treating the object as a particle. Is it reasonable to ignore air resistance? VISUALIZE: Use a pictorial representation. Establish a coordinate system with the x axis horizontal and the y axis vertical. Show important points in the motion on a sketch. Define symbols, and identify what you are trying to find. SOLVE: The acceleration is known: and . Thus, the problem becomes one of two-dimensional kinematics. The kinematic equations are , . is the same for the horizontal and vertical components of the motion. Find from one component, and then use that value for the other component. ASSESS: Check that your result has the correct units, is reasonable, and answers the question. Model Start by making simplifying assumptions: Model the rock as a particle in free fall. You can ignore air resistance because the rock is a relatively heavy object moving relatively slowly. Visualize Part A Which diagram represents an accurate sketch of the rock’s trajectory? Hint 1. The launch angle In a projectile’s motion, the angle of the initial velocity above the horizontal is called the launch angle. ANSWER: m/s  d m g m/s2 ax = 0 ay = −g xf = xi +vixt, yf = yi +viyt− g(t 1 2 )2 vfx = vix = constant, and vfy = viy − gt t t v i Typesetting math: 100% Typesetting math: 100% Correct Part B As stated in the strategy, choose a coordinate system where the x axis is horizontal and the y axis is vertical. Note that in the strategy, the y component of the projectile’s acceleration, , is taken to be negative. This implies that the positive y axis is upward. Use the same convention for your y axis, and take the positive x axis to be to the right. Where you choose your origin doesn’t change the answer to the question, but choosing an origin can make a problem easier to solve (even if only a bit). Usually it is nice if the majority of the quantities you are given and the quantity you are trying to solve for take positive values relative to your chosen origin. Given this goal, what location for the origin of the coordinate system would make this problem easiest? ANSWER: ay At ground level below the point where the rock is launched At the point where the rock strikes the ground At the peak of the trajectory At the point where the rock is released At ground level below the peak of the trajectory Typesetting math: 100% Correct It’s best to place the origin of the coordinate system at ground level below the launching point because in this way all the points of interest (the launching point and the landing point) will have positive coordinates. (Based on your experience, you know that it’s generally easier to work with positive coordinates.) Keep in mind, however, that this is an arbitrary choice. The correct solution of the problem will not depend on the location of the origin of your coordinate system. Now, define symbols representing initial and final position, velocity, and time. Your target variable is , the initial y coordinate of the rock. Your pictorial representation should be complete now, and similar to the picture below: Solve Part C Find the height from which the rock was launched. Express your answer in meters to three significant figures. yi yi Typesetting math: 100% Hint 1. How to approach the problem The time needed to move horizontally to the final position = 17.0 is the same time needed for the rock to rise from the initial position to the peak of its trajectory and then fall to the ground. Use the information you have about motion in the horizontal direction to solve for . Knowing this time will allow you to use the equations of motion for the vertical direction to solve for . Hint 2. Find the time spent in the air How long ( ) is the rock in the air? Express your answer in seconds to three significant figures. Hint 1. Determine which equation to use Which of the equations given in the strategy and shown below is the most appropriate to calculate the time the rock spent in the air? ANSWER: Hint 2. Find the x component of the initial velocity What is the x component of the rock’s initial velocity? Express your answer in meters per second to three significant figures. ANSWER: ANSWER: t xf = d m yi t yi t t xf = xi + vixt yf = yi + viyt− g(t 1 2 )2 vfy = viy − gt vix = 7.79 m/s Typesetting math: 100% Hint 3. Find the y component of the initial velocity What is the y component of the rock’s initial velocity? Express your answer in meters per second to three significant figures. ANSWER: ANSWER: Answer Requested Assess Part D A second rock is thrown straight upward with a speed 4.500 . If this rock takes 2.181 to fall to the ground, from what height was it released? Express your answer in meters to three significant figures. Hint 1. Identify the known variables What are the values of , , , and for the second rock? Take the positive y axis to be upward and the origin to be located on the ground where the rock lands. Express your answers to four significant figures in the units shown to the right, separated by commas. ANSWER: t = 2.18 s viy = 4.50 m/s yi = 13.5 m m/s s H yf viy t a Typesetting math: 100% Answer Requested Hint 2. Determine which equation to use to find the height Which equation should you use to find ? Keep in mind that if the positive y axis is upward and the origin is located on the ground, . ANSWER: ANSWER: Answer Requested Projectile motion is made up of two independent motions: uniform motion at constant velocity in the horizontal direction and free-fall motion in the vertical direction. Because both rocks were thrown with the same initial vertical velocity, 4.500 , and fell the same vertical distance of 13.5 , they were in the air for the same amount of time. This result was expected and helps to confirm that you did the calculation in Part C correctly. ± Arrow Hits Apple An arrow is shot at an angle of above the horizontal. The arrow hits a tree a horizontal distance away, at the same height above the ground as it was shot. Use for the magnitude of the acceleration due to gravity. Part A , , , = 0,4.500,2.181,-yf viy t a 9.810 m, m/s, s, m/s2 H yi = H yf = yi + viyt− g(t 1 2 )2 vfy = viy − gt = − 2g( − ) v2f y v2i y yf yi H = 13.5 m viy = m/s m  = 45 D = 220 m g = 9.8 m/s2 Typesetting math: 100% Find , the time that the arrow spends in the air. Answer numerically in seconds, to two significant figures. Hint 1. Find the initial upward component of velocity in terms of D. Introduce the (unknown) variables and for the initial components of velocity. Then use kinematics to relate them and solve for . What is the vertical component of the initial velocity? Express your answer symbolically in terms of and . Hint 1. Find Find the horizontal component of the initial velocity. Express your answer symbolically in terms of and given symbolic quantities. ANSWER: Hint 2. Find What is the vertical component of the initial velocity? Express your answer symbolically in terms of . ANSWER: ANSWER: ta vy0 vx0 ta vy0 ta D vx0 vx0 ta vx0 = D ta vy0 vy0 vx0 vy0 = vx0 vy0 = D ta Typesetting math: 100% Hint 2. Find the time of flight in terms of the initial vertical component of velocity. From the change in the vertical component of velocity, you should be able to find in terms of and . Give your answer in terms of and . Hint 1. Find When applied to the y-component of velocity, in this problem the formula for with constant acceleration is What is , the vertical component of velocity when the arrow hits the tree? Answer symbolically in terms of only. ANSWER: ANSWER: Hint 3. Put the algebra together to find symbolically. If you have an expression for the initial vertical velocity component in terms in terms of and , and another in terms of and , you should be able to eliminate this initial component to find an expression for Express your answer symbolically in terms of given variables. ANSWER: ta vy0 g vy0 g vy(ta) v(t) −g vy(t) = vy0 − g t vy(ta ) vy0 vy(ta) = −vy0 ta = 2vy0 g ta D ta g ta ta2 t2 = a 2D g Typesetting math: 100% ANSWER: Answer Requested Suppose someone drops an apple from a vertical distance of 6.0 meters, directly above the point where the arrow hits the tree. Part B How long after the arrow was shot should the apple be dropped, in order for the arrow to pierce the apple as the arrow hits the tree? Express your answer numerically in seconds, to two significant figures. Hint 1. When should the apple be dropped The apple should be dropped at the time equal to the total time it takes the arrow to reach the tree minus the time it takes the apple to fall 6.0 meters. Hint 2. Find the time it takes for the apple to fall 6.0 meters How long does it take an apple to fall 6.0 meters? Express your answer numerically in seconds, to two significant figures. ANSWER: Answer Requested ANSWER: ta = 6.7 s tf = 1.1 s td = 5.6 s Typesetting math: 100% Answer Requested Video Tutor: Ball Fired Upward from Accelerating Cart First, launch the video below. You will be asked to use your knowledge of physics to predict the outcome of an experiment. Then, close the video window and answer the questions at right. You can watch the video again at any point. Part A Consider the video you just watched. Suppose we replace the original launcher with one that fires the ball upward at twice the speed. We make no other changes. How far behind the cart will the ball land, compared to the distance in the original experiment? Hint 1. Determine how long the ball is in the air How will doubling the initial upward speed of the ball change the time the ball spends in the air? A kinematic equation may be helpful here. The time in the air will ANSWER: be cut in half. stay the same. double. quadruple. Typesetting math: 100% Hint 2. Determine the appropriate kinematic expression Which of the following kinematic equations correctly describes the horizontal distance between the ball and the cart at the moment the ball lands? The cart’s initial horizontal velocity is , its horizontal acceleration is , and is the time elapsed between launch and impact. ANSWER: ANSWER: Correct The ball will spend twice as much time in the air ( , where is the ball’s initial upward velocity), so it will land four times farther behind the cart: (where is the cart’s horizontal acceleration). Video Tutor: Ball Fired Upward from Moving Cart First, launch the video below. You will be asked to use your knowledge of physics to predict the outcome of an experiment. Then, close the video window and answer the questions at right. You can watch the video again at any point. d v0x ax t d = v0x t d = 1 2 axv0x t2 d = v0x t+ 1 2 axt2 d = 1 2 axt2 the same distance twice as far half as far four times as far by a factor not listed above t = 2v0y/g v0y d = 1 2 axt2 ax Typesetting math: 100% Part A The crew of a cargo plane wishes to drop a crate of supplies on a target below. To hit the target, when should the crew drop the crate? Ignore air resistance. Hint 1. How to approach the problem While the crate is on the plane, it shares the plane’s velocity. What is the crate’s velocity immediately after it is released? Hint 2. What affects the motion of the crate? Gravity will accelerate the crate downward. What, if anything, affects the crate’s horizontal motion? (Keep in mind that we are told to ignore air resistance, even though that’s not very realistic in this situation.) ANSWER: Correct At the moment it is released, the crate shares the plane’s horizontal velocity. In the absence of air resistance, the crate would remain directly below the plane as it fell. Score Summary: Your score on this assignment is 0%. Before the plane is directly over the target After the plane has flown over the target When the plane is directly over the target Typesetting math: 100% You received 0 out of a possible total of 0 points. Typesetting math: 100%

please email info@checkyourstudy.com
http://www.econlib.org/library/Smith/smWN1.html#B.I,%20Ch.1,%20Of%20the%20Division%20of%20Labor What does Smith mean by division of labor, and how does it affect production? A. He means that each person does their own work to benefit themselves by creating goods. This creates well-crafted goods. B. He argues that in order to become more efficient, we need to put everyone in the same workhouses and eliminate division. C. He says that the division of labor provides farmers with the opportunity to become involved in manufacturing. D. He means that each person makes one small part of a good very quickly, but this is bad for the quality of production overall. E. He means that by having each individual specialize in one thing, they can work together to create products more efficiently and effectively. Which of the following is NOT an example of the circumstances by which the division of labor improves efficiency? A. A doll-making company stops allowing each employee to make one whole doll each and instead appoints each employee to create one part of the doll. B. A family of rug makers buys a loom to speed up their production. C. A mechanic opens a new shop to be nearer to the market. D. A factory changes the responsibilities of its employees so that one group handles heavy boxes and the other group does precision sewing. E. A baker who used to make a dozen cookies at a time buys a giant mixer and oven that enable him to make 20 dozen cookies at a time. Considering the global system of states, what do you think the allegory of the pins has to offer? A. It suggests that there could be a natural harmony of interests among states because they can divide labor among themselves to the benefit of everyone. B. It suggests that states can never be secure enough to cooperate because every state is equally capable of producing the same things. C. It suggests that a central authority is necessary to help states cooperate, in the same way that a manager oversees operations at a factory. D. The allegory of the pins is a great way to think about how wars come about, because states won’t cooperate with each other like pin-makers do. E. The allegory of the pins shows us that there is no natural harmony of interests between states. Smith sees the development of industry, technology, and the division of labor as A. generally positive but not progressive. The lives of many people may improve, but the world will generally stay the same. B. generally positive and progressive. The world is improving because of these changes, and it will continue to improve. C. generally negative. The creation of new technologies and the division of labor are harmful to all humans, both the wealthy and the poor. D. generally negative. The creation of the division of labor only benefits the wealthy at the expense of the poor. E. both positive and negative. Smith thinks that technology hurts us, while the division of labor helps society progress and develop. http://www.youtube.com/watch?v=RUwS1uAdUcI What point is Hans Rosling trying to make when he describes the global health pre-test? A. He is trying to show how the average person has no idea of the true state of global health. B. He is trying to illustrate how we tend to carry around outdated notions about the state of global health. C. He is trying to make us see that the less-developed countries are far worse off than we ever thought. D. He is trying to drive home the idea that global health has not improved over time despite foreign aid and improvements in medicine. E. He is trying to warn us about the rapid growth in world population. Rosling shows us that we tend to think about global health in terms of “we and them.” Who are the “we” and who are the “them”? A. “We” refers to academics, students, and scholars; “them” refers to the uneducated. B. “We” refers to the average person; “them” refers to politicians and global leaders. C. “We” refers to the wealthy; “them” refers to the poor. D. “We” refers to the Western world; “them” refers to the Third World. E. “We” refers to students; “them” refers to professors. In the life expectancy and fertility rate demonstration, what do the statistics reveal? A. Over time, developed countries produced small families and long lives, whereas developing countries produced large families and short lives. B. The world today looks much like it did in 1962 despite our attempts to help poorer countries develop. C. All countries in the world, even the poorer ones, are trending toward longer lives and smaller families. D. Developed countries are trending toward smaller families but shorter lives. E. All countries tend to make gains and losses in fertility and lifespan, but in the long run there is no significant change. What point does Rosling make about life expectancy in Vietnam as compared to the United States? To what does he attribute the change? A. He indicates that economic change preceded social change. B. He suggests that markets and free trade resulted in the increase in life expectancy. C. He says that the data indicates that the Vietnam War contributed to the decrease in life expectancy during that time, but that it recovered shortly thereafter. D. He says that social change in Asia preceded economic change, and life expectancy in Vietnam increased despite the war. E. He indicates that Vietnam was equal to the United States in life expectancy before the war. According to Rosling, how are regional statistics about child survival rates and GDP potentially misleading? A. Countries have an incentive to lie about the actual survival rates because they want foreign assistance. B. Statistics for the individual countries in a region are often vastly different. C. Regional statistics give us a strong sense of how we can understand development within one region, but it does not allow us to compare across regions. D. The data available over time and from countries within regions is often poorly collected and incomplete. E. Child survival rates cannot be compared regionally, since each culture has a different sense of how important children are. What is Rosling’s main point about statistical databases? A. The data is available but not readily accessible, so we need to create networks to solve that problem. B. The data that comes from these databases is often flawed and unreliable. C. It doesn’t matter whether we have access to these databases because the data can’t be used in an interesting way. D. Statistics can’t tell us very much, but we should do our best to make use of the information we do have. E. The information that could be true is too hard to sort out from what isn’t true because we don’t know how strong the data really is. http://www.marxists.org/archive/lenin/works/1916/imp-hsc/ch10.htm#v22zz99h-298-GUESS Click the link at left to read Chapter 10 of Imperialism, The Highest Stage of Capitalism, then answer the questions below. According to Lenin, what is the fundamental source of a monopoly? A. It is a natural effect of human behavior. B. It is the result of governments and police systems. C. Its source is rooted in democracy. D. It comes from the concentration of production at a high stage. E. It is what follows a socialist system. What are the principal types or manifestations of monopoly capitalism? A. Monopolistic capitalist associations like cartels, syndicates and trusts; and monopolies as a result of colonial policy. B. Monopolization of raw materials and monopolization of finance capital. C. Monopolization of governing structures and monopolies of oligarchies. D. Monopolist capitalist associations like cartels, syndicates and trusts; and monopolies as a result of colonial policy AND monopolization of raw materials and monopolization of finance capital. E. Monopolization of raw materials and monopolization of finance capital AND monopolization of governing structures and monopolies of oligarchies. What is the definition of a rentier state according to Lenin? A. A state that colonizes other states. B. A state whose bourgeoisie live off the export of capital. C. A poor state. D. A wealthy state. E. A colonized state. Overall Lenin’s analysis of the state of capitalism is concerned with: A. The interactions between states. B. The interactions within states. C. The ownership of industry and organizations. D. The interactions within states AND the ownership of industry and organizations. E. All of these options. http://view.vzaar.com/1194665/flashplayer Watch the video at left, and then answer the questions below. The Marshall Plan was developed by the United States after World War II. What was its purpose? A. to feed the hungry of Europe B. to stem the spread of communism C. to maintain an American military presence in Europe D. to feed the hungry of Europe AND to stem the spread of communism E. to stem the spread of communism AND to maintain an American military presence in Europe What kind of aid was sent at first? A. foods, fertilizers, and machines for agriculture B. books, paper, and radios for education C. clothing, medical supplies, and construction equipment D. mostly cash in the form of loans and grants E. people with business expertise to help develop the economy What kind of aid did the United States send to Greece to help its farmers? A. tractors B. mules C. seeds D. fertilizer E. all of these options What was one way that the United States influenced public opinion in Italy during the elections described in the video? A. The United States provided significant food aid to Italy so that the Italians would be inclined to vote against the Communists. B. The Italians had been impressed by the strength and loyalty of the American soldiers, and were inclined to listen to them during the elections. C. There was a large number of young Italians who followed American fashion and culture. D. Italian immigrants in the United States wrote letters to their families in Italy urging them not to vote for Communists. E. The Greeks showed the Italians how much the Americans had helped them, warning that supporting a Communist candidate would mean sacrificing American aid. How did Pope Pius XII undermine the strength of the Communist Party in Italy? A. He encouraged Italians to go out and vote. B. He warned that the Communist Party would legalize abortion. C. He excommunicated many members of the Communist Party. D. He made a speech in support of capitalism. E. He declared that Communists should not be baptized. http://www.youtube.com/watch?v=KVhWqwnZ1eM Use the video at left to answer the questions below. Hans Rosling shares how his students discuss “we” versus “them.” To whom are his students referring? A. the United States and Mexico B. Christians and Muslims C. Democrats and Republicans D. Europe and Asia E. none of these options According to Rosling, what factors contribute to a better quality of life for people in developing countries? A. family planning B. soap and water C. investment D. vaccinations E. all of these options Using his data, Rosling demonstrates a great shift in Mexico. What change does his data demonstrate? A. a decrease in drug usage B. a decrease in the number of jobs available C. an increase in average life expenctancy D. an increase in the rate of violent crime E. all of these options Instead of “developing” and “developed,” Rosling divides countries into four categories. Which of the following is NOT one of them? A. high-income countries B. middle-income countries C. low-income countries D. no-income countries E. collapsing countries Rosling discusses the increased life expectancy in both China and the United States. How are the situations different? A. The U.S. and China are on different continents. B. The life expectancy in China rose much higher than it did in the U.S. C. China first expanded its life expectancy and then grew economically, whereas the U.S. did the reverse. D. Average income and life expectancy steadily increased in the U.S., but they steadily decreased in China. E. all of these options Rosling shows a chart that demonstrates the regional income distribution of the world from 1970 to 2015. During that time, what has happened in South and East Asia? A. Money has flowed out of Asia to developing countries in Africa. B. The average income of citizens of South and East Asia has increased over the last 30 years. C. The average income of citizens of South and East Asia has decreased over the last 30 years. D. The average income of citizens of South and East Asia has surpassed that of Europe and North America. E. There has been no change. Click here to access GapMinder, the data visualizer that Hans Rosling uses. In 2010, which of the following countries had both a higher per-capita GDP and a higher life expectancy than the United States? A. France B. Japan C. Denmark D. Singapore E. Kuwait http://www.garretthardinsociety.org/articles/art_tragedy_of_the_commons.html http://www.youtube.com/watch?v=8a4S23uXIcM The Tragedy of the Commons What is the rough definition of the “commons” given in the article? A. any private property on which others trespass B. behavior that everyone considers to be normal C. a cow that lives in a herd D. government-administered benefits, like unemployment or Social Security E. a shared resource What does Hardin mean by describing pollution as a reverse tragedy of the commons? A. Rather than causing a problem, it resolves a problem. B. Pollution costs us money rather than making us money. C. We are putting something into the commons rather than removing something from it. D. It starts at the other end of the biological pyramid. E. Humans see less of it as time goes on. Hardin says “the air and waters surrounding us cannot readily be fenced, and so the tragedy of the commons as a cesspool must be prevented by different means.” What are those means? A. establishing more international treaties to protect the environment B. using laws or taxes to make the polluter pay for pollution C. punishing consumers for generating waste D. raising awareness about environmental issues E. developing greener products Pacific Garbage Dump According to the news report, what percent of the Gyre is made of plastic? A. 50 percent B. 60 percent C. 70 percent D. 80 percent E. 90 percent Where does the majority of the plastic in the Gyre come from? A. barges that dump trash in the ocean B. storm drains from land C. people throwing litter off boats into the ocean D. remnants from movie sets filmed at sea E. fishing boats processing their catch What does Charles Moore mean by the “throwaway concept”? A. the habitual use of disposable plastic packaging B. the mistaken view that marine ecosystems are infinitely renewable C. a general lack of interest in recycling D. the willingness to discard effective but small-scale environmental policies in deference to broader E. people throwing away their lives in pursuit of money In what way does the Great Pacific Gyre represent issues like global warming a tragedy of the commons? A. because all the plastic trash in it comes from the United States B. because it kills the albatross and makes it impossible for them to reproduce C. surbecause the countries rounding the Pacific Ocean are polluting the water in a way that affects the quality of the resource for all, but no one is specifically accountable for it D. because it causes marine life to compete for increasingly scarce nutrients in the ocean E. because nations in the region all collectively agreed to dump their trash in the Pacific http://www.npr.org/news/specials/climate/video/ http://ngm.nationalgeographic.com/climateconnections/climate-map http://www.npr.org/news/specials/climate/video/wildchronicles.html Use the links provided at left to answer the questions below. Global Warming: It’s All About Carbon How does carbon give us fuel? A. When you burn things that contain carbon the bonds break, giving off energy. B. Burning things creates carbon out of other elements as a result of combustion. C. Carbon is created after oxygen and hydrogen get released. D. Carbon bonds are created thereby giving off energy. E. Carbon is made into fuel by refining oil. National Geographic Climate Map What geographic areas have seen the most significant changes in temperature? A. The African continent. B. The Pacific Ocean. C. The Atlantic Ocean. D. The Arctic Ocean. E. The Indian Ocean. Why does it matter that rain fall steadily rather than in downpours? A. For those countries accustomed to steady rain fall, downpours are actually more efficient ways to catch water. B. Downpours in regions accustomed to steady fall makes them more prone to flooding and damage. C. In general, as long as regions get either steady fall or downpours most things will stay the same. D. Downpours are always more beneficial to crop growth than steady rain. E. Steady rain is always more beneficial to crop growth than downpours. Climate Change Threatens Kona Coffee What is unique about the climate in Hawaii, making it a good place to grow coffee? A. The elevation is high, the nights are cool and the days are humid. B. The elevation is low, the nights are warm and the days are dry. C. The elevation is high, the nights are warm and the days are dry. D. The elevation is low, the nights are cool and the days are dry. E. The elevation is high, the nights are warm and the days are humid. What specific temperature pattern have experts noted about the region where Kona coffee is grown in Hawaii? A. There has been no significant change but the bean production has dropped. B. The nights have warmed up, even though the days have cooled. C. There has been an increase in bean production with the change in climate. D. The nights have cooled even more so than before. E. There has been universally hot days all the way around.

http://www.econlib.org/library/Smith/smWN1.html#B.I,%20Ch.1,%20Of%20the%20Division%20of%20Labor What does Smith mean by division of labor, and how does it affect production? A. He means that each person does their own work to benefit themselves by creating goods. This creates well-crafted goods. B. He argues that in order to become more efficient, we need to put everyone in the same workhouses and eliminate division. C. He says that the division of labor provides farmers with the opportunity to become involved in manufacturing. D. He means that each person makes one small part of a good very quickly, but this is bad for the quality of production overall. E. He means that by having each individual specialize in one thing, they can work together to create products more efficiently and effectively. Which of the following is NOT an example of the circumstances by which the division of labor improves efficiency? A. A doll-making company stops allowing each employee to make one whole doll each and instead appoints each employee to create one part of the doll. B. A family of rug makers buys a loom to speed up their production. C. A mechanic opens a new shop to be nearer to the market. D. A factory changes the responsibilities of its employees so that one group handles heavy boxes and the other group does precision sewing. E. A baker who used to make a dozen cookies at a time buys a giant mixer and oven that enable him to make 20 dozen cookies at a time. Considering the global system of states, what do you think the allegory of the pins has to offer? A. It suggests that there could be a natural harmony of interests among states because they can divide labor among themselves to the benefit of everyone. B. It suggests that states can never be secure enough to cooperate because every state is equally capable of producing the same things. C. It suggests that a central authority is necessary to help states cooperate, in the same way that a manager oversees operations at a factory. D. The allegory of the pins is a great way to think about how wars come about, because states won’t cooperate with each other like pin-makers do. E. The allegory of the pins shows us that there is no natural harmony of interests between states. Smith sees the development of industry, technology, and the division of labor as A. generally positive but not progressive. The lives of many people may improve, but the world will generally stay the same. B. generally positive and progressive. The world is improving because of these changes, and it will continue to improve. C. generally negative. The creation of new technologies and the division of labor are harmful to all humans, both the wealthy and the poor. D. generally negative. The creation of the division of labor only benefits the wealthy at the expense of the poor. E. both positive and negative. Smith thinks that technology hurts us, while the division of labor helps society progress and develop. http://www.youtube.com/watch?v=RUwS1uAdUcI What point is Hans Rosling trying to make when he describes the global health pre-test? A. He is trying to show how the average person has no idea of the true state of global health. B. He is trying to illustrate how we tend to carry around outdated notions about the state of global health. C. He is trying to make us see that the less-developed countries are far worse off than we ever thought. D. He is trying to drive home the idea that global health has not improved over time despite foreign aid and improvements in medicine. E. He is trying to warn us about the rapid growth in world population. Rosling shows us that we tend to think about global health in terms of “we and them.” Who are the “we” and who are the “them”? A. “We” refers to academics, students, and scholars; “them” refers to the uneducated. B. “We” refers to the average person; “them” refers to politicians and global leaders. C. “We” refers to the wealthy; “them” refers to the poor. D. “We” refers to the Western world; “them” refers to the Third World. E. “We” refers to students; “them” refers to professors. In the life expectancy and fertility rate demonstration, what do the statistics reveal? A. Over time, developed countries produced small families and long lives, whereas developing countries produced large families and short lives. B. The world today looks much like it did in 1962 despite our attempts to help poorer countries develop. C. All countries in the world, even the poorer ones, are trending toward longer lives and smaller families. D. Developed countries are trending toward smaller families but shorter lives. E. All countries tend to make gains and losses in fertility and lifespan, but in the long run there is no significant change. What point does Rosling make about life expectancy in Vietnam as compared to the United States? To what does he attribute the change? A. He indicates that economic change preceded social change. B. He suggests that markets and free trade resulted in the increase in life expectancy. C. He says that the data indicates that the Vietnam War contributed to the decrease in life expectancy during that time, but that it recovered shortly thereafter. D. He says that social change in Asia preceded economic change, and life expectancy in Vietnam increased despite the war. E. He indicates that Vietnam was equal to the United States in life expectancy before the war. According to Rosling, how are regional statistics about child survival rates and GDP potentially misleading? A. Countries have an incentive to lie about the actual survival rates because they want foreign assistance. B. Statistics for the individual countries in a region are often vastly different. C. Regional statistics give us a strong sense of how we can understand development within one region, but it does not allow us to compare across regions. D. The data available over time and from countries within regions is often poorly collected and incomplete. E. Child survival rates cannot be compared regionally, since each culture has a different sense of how important children are. What is Rosling’s main point about statistical databases? A. The data is available but not readily accessible, so we need to create networks to solve that problem. B. The data that comes from these databases is often flawed and unreliable. C. It doesn’t matter whether we have access to these databases because the data can’t be used in an interesting way. D. Statistics can’t tell us very much, but we should do our best to make use of the information we do have. E. The information that could be true is too hard to sort out from what isn’t true because we don’t know how strong the data really is. http://www.marxists.org/archive/lenin/works/1916/imp-hsc/ch10.htm#v22zz99h-298-GUESS Click the link at left to read Chapter 10 of Imperialism, The Highest Stage of Capitalism, then answer the questions below. According to Lenin, what is the fundamental source of a monopoly? A. It is a natural effect of human behavior. B. It is the result of governments and police systems. C. Its source is rooted in democracy. D. It comes from the concentration of production at a high stage. E. It is what follows a socialist system. What are the principal types or manifestations of monopoly capitalism? A. Monopolistic capitalist associations like cartels, syndicates and trusts; and monopolies as a result of colonial policy. B. Monopolization of raw materials and monopolization of finance capital. C. Monopolization of governing structures and monopolies of oligarchies. D. Monopolist capitalist associations like cartels, syndicates and trusts; and monopolies as a result of colonial policy AND monopolization of raw materials and monopolization of finance capital. E. Monopolization of raw materials and monopolization of finance capital AND monopolization of governing structures and monopolies of oligarchies. What is the definition of a rentier state according to Lenin? A. A state that colonizes other states. B. A state whose bourgeoisie live off the export of capital. C. A poor state. D. A wealthy state. E. A colonized state. Overall Lenin’s analysis of the state of capitalism is concerned with: A. The interactions between states. B. The interactions within states. C. The ownership of industry and organizations. D. The interactions within states AND the ownership of industry and organizations. E. All of these options. http://view.vzaar.com/1194665/flashplayer Watch the video at left, and then answer the questions below. The Marshall Plan was developed by the United States after World War II. What was its purpose? A. to feed the hungry of Europe B. to stem the spread of communism C. to maintain an American military presence in Europe D. to feed the hungry of Europe AND to stem the spread of communism E. to stem the spread of communism AND to maintain an American military presence in Europe What kind of aid was sent at first? A. foods, fertilizers, and machines for agriculture B. books, paper, and radios for education C. clothing, medical supplies, and construction equipment D. mostly cash in the form of loans and grants E. people with business expertise to help develop the economy What kind of aid did the United States send to Greece to help its farmers? A. tractors B. mules C. seeds D. fertilizer E. all of these options What was one way that the United States influenced public opinion in Italy during the elections described in the video? A. The United States provided significant food aid to Italy so that the Italians would be inclined to vote against the Communists. B. The Italians had been impressed by the strength and loyalty of the American soldiers, and were inclined to listen to them during the elections. C. There was a large number of young Italians who followed American fashion and culture. D. Italian immigrants in the United States wrote letters to their families in Italy urging them not to vote for Communists. E. The Greeks showed the Italians how much the Americans had helped them, warning that supporting a Communist candidate would mean sacrificing American aid. How did Pope Pius XII undermine the strength of the Communist Party in Italy? A. He encouraged Italians to go out and vote. B. He warned that the Communist Party would legalize abortion. C. He excommunicated many members of the Communist Party. D. He made a speech in support of capitalism. E. He declared that Communists should not be baptized. http://www.youtube.com/watch?v=KVhWqwnZ1eM Use the video at left to answer the questions below. Hans Rosling shares how his students discuss “we” versus “them.” To whom are his students referring? A. the United States and Mexico B. Christians and Muslims C. Democrats and Republicans D. Europe and Asia E. none of these options According to Rosling, what factors contribute to a better quality of life for people in developing countries? A. family planning B. soap and water C. investment D. vaccinations E. all of these options Using his data, Rosling demonstrates a great shift in Mexico. What change does his data demonstrate? A. a decrease in drug usage B. a decrease in the number of jobs available C. an increase in average life expenctancy D. an increase in the rate of violent crime E. all of these options Instead of “developing” and “developed,” Rosling divides countries into four categories. Which of the following is NOT one of them? A. high-income countries B. middle-income countries C. low-income countries D. no-income countries E. collapsing countries Rosling discusses the increased life expectancy in both China and the United States. How are the situations different? A. The U.S. and China are on different continents. B. The life expectancy in China rose much higher than it did in the U.S. C. China first expanded its life expectancy and then grew economically, whereas the U.S. did the reverse. D. Average income and life expectancy steadily increased in the U.S., but they steadily decreased in China. E. all of these options Rosling shows a chart that demonstrates the regional income distribution of the world from 1970 to 2015. During that time, what has happened in South and East Asia? A. Money has flowed out of Asia to developing countries in Africa. B. The average income of citizens of South and East Asia has increased over the last 30 years. C. The average income of citizens of South and East Asia has decreased over the last 30 years. D. The average income of citizens of South and East Asia has surpassed that of Europe and North America. E. There has been no change. Click here to access GapMinder, the data visualizer that Hans Rosling uses. In 2010, which of the following countries had both a higher per-capita GDP and a higher life expectancy than the United States? A. France B. Japan C. Denmark D. Singapore E. Kuwait http://www.garretthardinsociety.org/articles/art_tragedy_of_the_commons.html http://www.youtube.com/watch?v=8a4S23uXIcM The Tragedy of the Commons What is the rough definition of the “commons” given in the article? A. any private property on which others trespass B. behavior that everyone considers to be normal C. a cow that lives in a herd D. government-administered benefits, like unemployment or Social Security E. a shared resource What does Hardin mean by describing pollution as a reverse tragedy of the commons? A. Rather than causing a problem, it resolves a problem. B. Pollution costs us money rather than making us money. C. We are putting something into the commons rather than removing something from it. D. It starts at the other end of the biological pyramid. E. Humans see less of it as time goes on. Hardin says “the air and waters surrounding us cannot readily be fenced, and so the tragedy of the commons as a cesspool must be prevented by different means.” What are those means? A. establishing more international treaties to protect the environment B. using laws or taxes to make the polluter pay for pollution C. punishing consumers for generating waste D. raising awareness about environmental issues E. developing greener products Pacific Garbage Dump According to the news report, what percent of the Gyre is made of plastic? A. 50 percent B. 60 percent C. 70 percent D. 80 percent E. 90 percent Where does the majority of the plastic in the Gyre come from? A. barges that dump trash in the ocean B. storm drains from land C. people throwing litter off boats into the ocean D. remnants from movie sets filmed at sea E. fishing boats processing their catch What does Charles Moore mean by the “throwaway concept”? A. the habitual use of disposable plastic packaging B. the mistaken view that marine ecosystems are infinitely renewable C. a general lack of interest in recycling D. the willingness to discard effective but small-scale environmental policies in deference to broader E. people throwing away their lives in pursuit of money In what way does the Great Pacific Gyre represent issues like global warming a tragedy of the commons? A. because all the plastic trash in it comes from the United States B. because it kills the albatross and makes it impossible for them to reproduce C. surbecause the countries rounding the Pacific Ocean are polluting the water in a way that affects the quality of the resource for all, but no one is specifically accountable for it D. because it causes marine life to compete for increasingly scarce nutrients in the ocean E. because nations in the region all collectively agreed to dump their trash in the Pacific http://www.npr.org/news/specials/climate/video/ http://ngm.nationalgeographic.com/climateconnections/climate-map http://www.npr.org/news/specials/climate/video/wildchronicles.html Use the links provided at left to answer the questions below. Global Warming: It’s All About Carbon How does carbon give us fuel? A. When you burn things that contain carbon the bonds break, giving off energy. B. Burning things creates carbon out of other elements as a result of combustion. C. Carbon is created after oxygen and hydrogen get released. D. Carbon bonds are created thereby giving off energy. E. Carbon is made into fuel by refining oil. National Geographic Climate Map What geographic areas have seen the most significant changes in temperature? A. The African continent. B. The Pacific Ocean. C. The Atlantic Ocean. D. The Arctic Ocean. E. The Indian Ocean. Why does it matter that rain fall steadily rather than in downpours? A. For those countries accustomed to steady rain fall, downpours are actually more efficient ways to catch water. B. Downpours in regions accustomed to steady fall makes them more prone to flooding and damage. C. In general, as long as regions get either steady fall or downpours most things will stay the same. D. Downpours are always more beneficial to crop growth than steady rain. E. Steady rain is always more beneficial to crop growth than downpours. Climate Change Threatens Kona Coffee What is unique about the climate in Hawaii, making it a good place to grow coffee? A. The elevation is high, the nights are cool and the days are humid. B. The elevation is low, the nights are warm and the days are dry. C. The elevation is high, the nights are warm and the days are dry. D. The elevation is low, the nights are cool and the days are dry. E. The elevation is high, the nights are warm and the days are humid. What specific temperature pattern have experts noted about the region where Kona coffee is grown in Hawaii? A. There has been no significant change but the bean production has dropped. B. The nights have warmed up, even though the days have cooled. C. There has been an increase in bean production with the change in climate. D. The nights have cooled even more so than before. E. There has been universally hot days all the way around.

http://www.econlib.org/library/Smith/smWN1.html#B.I,%20Ch.1,%20Of%20the%20Division%20of%20Labor What does Smith mean by division of labor, and … Read More...
Name___________________________________ Period_____ Investigation: Making Waves PART I: Objectives: • Learn vocabulary describing waves • Calculate the speed of a wave • Understand how amplitude affects the speed of a wave • Understand how frequency and wavelength affect the speed of a wave Open this web site: http://phet.colorado.edu/new/simulations/sims.php?sim=Wave_on_a_String You can click on Run Now! to run the simulation online, or Run Offline to save it to your desktop. It might run faster this way. Start by Wiggling the Wrench. Spend about 5 minutes experimenting with the Tension, Manual/Pulse/Oscillate, Fixed/Loose/No end, and changing the Amplitude, Frequency and Damping. Click on Show Rulers and Timer. Practice moving the rulers around and starting/resetting the timer. Click on the Pause/Play and Step buttons to see how they work. Use these settings: Pulse, Amplitude=50, Pulse Width=35, Damping=0, Tension at High and No End. NOTE that the amplitude is just a relative scale (not centimeters). Send a single pulse down the string. This is called a TRANSVERSE PULSE. Watch the motion of the green dots.  1. As the pulse goes by from left to right, in what direction does the string move? ________________________________________________________________________________________________________________________________________________  2. A definition of TRANSVERSE is “lying across”. Why is TRANSVERSE a good name for the wave you just observed? ________________________________________________________________________________________________________________________________________________ Make another pulse, and then PAUSE the wave. Use the vertical ruler to measure the amplitude of the wave in centimeters. This is the distance from the dotted orange line to the crest of the wave. Record the amplitude in Table 1 in the first row. Now, measure the time for a pulse to travel 100 cm. To do this: • Reset the clock to 0:00 and reset the generator • Click Pause/Play—it should say PAUSED on the screen • Click Pulse • Click Pause/Play again to start a timed pulse. Pause again just as the crest (peak) of the pulse touches the window 100 cm away. Record the time for a pulse to travel 100 cm in Table 1. Run 3 time trials, and record in the table. Calculate the average time. Now, measure the amplitude and timing of pulses for two other amplitudes (one smaller than 50, one larger than 50). Do three trials at each amplitude and calculate the average times. Calculate the average wave speed for each of the three amplitudes. See below for a sample calculation. Table 1 Your measured amplitude, cm Time for pulse to travel 100 cm, seconds Average time, seconds Speed=length of string / average time Example of speed calculation: Speed = string length/ average time Speed = 100 cm/2 seconds = 50 cm/second  3. How does the amplitude of a wave affect the speed of a wave? ________________________________________________________________________ Use these settings: Oscillate, Fixed end. Try amplitude=20, frequency=51, damping=0. The result is called a periodic wave. 4. Describe the appearance of the wave you created. ________________________________________________________________________________________________________________________________________________________________________________________________________________________ You should see waves that do not move along the string. You will also see points where the string does not move at all. These waves are called STANDING WAVES. The points where the wave doesn’t move are called NODES. Pause the simulation.  5. Draw the standing wave in the box below, labeling the AMPLITUDE, WAVELENGTH and NODES of a standing wave. Use these settings: Amplitude=20, Frequency=50, Damping=0, Oscillate, No End. Reset the clock. You can also measure the wave frequency. To do this, you should pair up with another student if possible. Watch the piston go up and down to make the wave. One up and down motion represents one wave. Use the clock to measure the time required for 10 complete cycles or waves. You will also need to PAUSE the wave to measure the wavelength of the wave in centimeters (cm). The frequency of the wave is calculated in the following way: Frequency = 10 waves/# seconds for 10 cycles For example, 10 waves/5 seconds = 2 cycles per second, or 2 Hertz. Make several waves by changing the wave frequency—use numbers over 30 on the scale. For each wave, measure the wavelength using the ruler. Now, calculate the frequency. See the example in the first row of Table 2. Record the wavelength and frequency of three waves with different wavelengths. Wavelength (cm) Frequency (cycles/second or Hertz) Speed (cm/s) = Wavelength x frequency 33 cm 10 waves/5.45 sec = 1.8 Hertz 33 cm x 1.8 Hertz = 59.4 cm/second Based on the equation used to calculate the speed of a wave, answer questions 6 and 7.  6. If you increase the wavelength of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________  7. If you increase the frequency of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________ Part II: Objectives: • Interpret a 2D top view picture of a wave • Identify areas of constructive and destructive interference in 2D • Predict the behavior of water, sound, or light when you have two sources o What will happen in constructive areas o What will happen in destructive areas 1) Open the “Wave Interference” simulation from the PhET website (in Sound & Waves) 2) On the water simulation, what does the crest (peak) of the wave look like in the top view? What does the trough look like? 3) When you add two drips, what changes about the waves’ patterns? 4) What does the wave look like in the area that the two waves constructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 5) What does the wave look like in the area that the two waves destructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 6) Switch to the sound simulation. a. What do you think will happen when you put two speakers next to each other? b. Why do you think this will happen? c. Try it (putting two speakers together) and tell me what happened. 7) Now switch to the light simulation. a. What do you think will happen when you put two light sources next to each other? b. Why do you think this will happen? c. Try it (putting two light sources together) and tell me what happened. d. What happens when you use one light source and two slits? 8) What is similar about all three of these simulations (i.e. water, sound & light)? 9) How do I know that these things are waves and not particles? (Think about what would happen in the two slit experiment if they were particles).

Name___________________________________ Period_____ Investigation: Making Waves PART I: Objectives: • Learn vocabulary describing waves • Calculate the speed of a wave • Understand how amplitude affects the speed of a wave • Understand how frequency and wavelength affect the speed of a wave Open this web site: http://phet.colorado.edu/new/simulations/sims.php?sim=Wave_on_a_String You can click on Run Now! to run the simulation online, or Run Offline to save it to your desktop. It might run faster this way. Start by Wiggling the Wrench. Spend about 5 minutes experimenting with the Tension, Manual/Pulse/Oscillate, Fixed/Loose/No end, and changing the Amplitude, Frequency and Damping. Click on Show Rulers and Timer. Practice moving the rulers around and starting/resetting the timer. Click on the Pause/Play and Step buttons to see how they work. Use these settings: Pulse, Amplitude=50, Pulse Width=35, Damping=0, Tension at High and No End. NOTE that the amplitude is just a relative scale (not centimeters). Send a single pulse down the string. This is called a TRANSVERSE PULSE. Watch the motion of the green dots.  1. As the pulse goes by from left to right, in what direction does the string move? ________________________________________________________________________________________________________________________________________________  2. A definition of TRANSVERSE is “lying across”. Why is TRANSVERSE a good name for the wave you just observed? ________________________________________________________________________________________________________________________________________________ Make another pulse, and then PAUSE the wave. Use the vertical ruler to measure the amplitude of the wave in centimeters. This is the distance from the dotted orange line to the crest of the wave. Record the amplitude in Table 1 in the first row. Now, measure the time for a pulse to travel 100 cm. To do this: • Reset the clock to 0:00 and reset the generator • Click Pause/Play—it should say PAUSED on the screen • Click Pulse • Click Pause/Play again to start a timed pulse. Pause again just as the crest (peak) of the pulse touches the window 100 cm away. Record the time for a pulse to travel 100 cm in Table 1. Run 3 time trials, and record in the table. Calculate the average time. Now, measure the amplitude and timing of pulses for two other amplitudes (one smaller than 50, one larger than 50). Do three trials at each amplitude and calculate the average times. Calculate the average wave speed for each of the three amplitudes. See below for a sample calculation. Table 1 Your measured amplitude, cm Time for pulse to travel 100 cm, seconds Average time, seconds Speed=length of string / average time Example of speed calculation: Speed = string length/ average time Speed = 100 cm/2 seconds = 50 cm/second  3. How does the amplitude of a wave affect the speed of a wave? ________________________________________________________________________ Use these settings: Oscillate, Fixed end. Try amplitude=20, frequency=51, damping=0. The result is called a periodic wave. 4. Describe the appearance of the wave you created. ________________________________________________________________________________________________________________________________________________________________________________________________________________________ You should see waves that do not move along the string. You will also see points where the string does not move at all. These waves are called STANDING WAVES. The points where the wave doesn’t move are called NODES. Pause the simulation.  5. Draw the standing wave in the box below, labeling the AMPLITUDE, WAVELENGTH and NODES of a standing wave. Use these settings: Amplitude=20, Frequency=50, Damping=0, Oscillate, No End. Reset the clock. You can also measure the wave frequency. To do this, you should pair up with another student if possible. Watch the piston go up and down to make the wave. One up and down motion represents one wave. Use the clock to measure the time required for 10 complete cycles or waves. You will also need to PAUSE the wave to measure the wavelength of the wave in centimeters (cm). The frequency of the wave is calculated in the following way: Frequency = 10 waves/# seconds for 10 cycles For example, 10 waves/5 seconds = 2 cycles per second, or 2 Hertz. Make several waves by changing the wave frequency—use numbers over 30 on the scale. For each wave, measure the wavelength using the ruler. Now, calculate the frequency. See the example in the first row of Table 2. Record the wavelength and frequency of three waves with different wavelengths. Wavelength (cm) Frequency (cycles/second or Hertz) Speed (cm/s) = Wavelength x frequency 33 cm 10 waves/5.45 sec = 1.8 Hertz 33 cm x 1.8 Hertz = 59.4 cm/second Based on the equation used to calculate the speed of a wave, answer questions 6 and 7.  6. If you increase the wavelength of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________  7. If you increase the frequency of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________ Part II: Objectives: • Interpret a 2D top view picture of a wave • Identify areas of constructive and destructive interference in 2D • Predict the behavior of water, sound, or light when you have two sources o What will happen in constructive areas o What will happen in destructive areas 1) Open the “Wave Interference” simulation from the PhET website (in Sound & Waves) 2) On the water simulation, what does the crest (peak) of the wave look like in the top view? What does the trough look like? 3) When you add two drips, what changes about the waves’ patterns? 4) What does the wave look like in the area that the two waves constructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 5) What does the wave look like in the area that the two waves destructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 6) Switch to the sound simulation. a. What do you think will happen when you put two speakers next to each other? b. Why do you think this will happen? c. Try it (putting two speakers together) and tell me what happened. 7) Now switch to the light simulation. a. What do you think will happen when you put two light sources next to each other? b. Why do you think this will happen? c. Try it (putting two light sources together) and tell me what happened. d. What happens when you use one light source and two slits? 8) What is similar about all three of these simulations (i.e. water, sound & light)? 9) How do I know that these things are waves and not particles? (Think about what would happen in the two slit experiment if they were particles).

“No Bats in the Belfry” by Dechaine and Johnson Page 1 by Jennifer M. Dechaine1,2 and James E. Johnson1 1Department of Biological Sciences 2Department of Science Education Central Washington University, Ellensburg, WA NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Part I – The Basic Question Introduction Imagine going out for a brisk winter snowshoe and suddenly stumbling upon hundreds of bat carcasses littering the forest floor. Unfortunately, this unsettling sight has become all too common in the United States (Figure 1). White-nose syndrome (WNS), first discovered in 2006, has now spread to 20 states and has led to the deaths of over 5.5 million bats (as of January 2012). WNS is a disease caused by the fungus, Pseudogymnoascus destructans. Bats infected with WNS develop white fuzz on their noses (Figure 2, next page) and often exhibit unnatural behavior, such as flying outside during the winter when they should be hibernating. WNS affects at least six different bat species in the United States and quickly decimates bat populations (colony mortality is commonly greater than 90%). Scientists have predicted that if deaths continue at the current rate, several bat species will become locally extinct within 20 years. Bats provide natural pest control by eating harmful insects, such as crop pests and disease carrying insect species, and losing bat populations would have devastating consequences for the U.S. economy. Researchers have sprung into action to study how bats become infected with and transmit P. destructans, but a key component of this research is determining where the fungus came from in the first place. Some have suggested that it is an invasive species from a different country while others think it is a North American fungal species that has recently become better able to cause disease. In this case study, we examine the origin of P. destructans causing WNS in North America. Some Other Important Observations • WNS was first documented at four cave sites in New York State in 2006. • The fungus can be spread among bats by direct contact or spores can be transferred between caves by humans (on clothing) or other animals. • European strains of the fungus occur in low levels across Europe but have led to few bat deaths there. • Bats with WNS frequently awake during hibernation, causing them to use important fat reserves, leading to death. No Bats in the Belfry: The Origin of White- Nose Syndrome in Little Brown Bats Figure 1. Many bats dead in winter from white-nose syndrome. NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 2 Questions 1. What is the basic question of this study and why is it interesting? 2. What specific testable hypotheses can you develop to explain the observations and answer the basic question of this study? Write at least two alternative hypotheses. 3. What predictions about the effects of European strains of P. destructans on North American bats can you make if your hypotheses are correct? Write at least one prediction for each of your hypotheses. Figure 2. White fuzz on the muzzle of a little brown bat indicating infection by the disease. NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 3 Part II – The Hypothesis As discussed in Part I, researchers had preliminary data suggesting that the pathogen causing WNS is an invasive fungal species (P. destructans) brought to North America from Europe. They had also observed that P. destructans occurs on European bats but rarely causes their death. Preliminary research also suggested that one reason that bats have been dying from WNS is that the disorder arouses them from hibernation, causing the bats to waste fat reserves flying during the winter when food is not readily available. These observations led researchers to speculate that European P. destructans will affect North American bat hibernation at least as severely as does North American P. destructans (Warnecke et al. 2012). Questions 1. Explicitly state the researchers’ null (H0 ) and alternative hypotheses (HA) for this study. 2. Describe an experiment you could use to differentiate between these hypotheses (H0 and HA). NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 4 Part III – Experiments and Observations In 2010, Lisa Warnecke and colleagues (2012) isolated P. destructans fungal spores from Europe and North America. They collected 54 male little brown bats (Myotis lucifugus) from the wild and divided these bats equally into three treatment groups. • Group 1 was inoculated with the North American P. destructans spores (NAGd treatment). • Group 2 was inoculated with the European P. destructans spores (EUGd treatment). • Group 3 was inoculated using the inoculation serum with no spores (Control treatment). All three groups were put into separate dark chambers that simulated the environmental conditions of a cave. All bats began hibernating within the first week of the study. The researchers used infrared cameras to examine the bats’ hibernation over four consecutive intervals of 26 days each. They then used the cameras to determine the total number of times a bat was aroused from hibernation during each interval. Questions 1. Use the graph below to predict what the results will look like if the null hypothesis is supported. The total arousal counts in the control treatment at each interval is graphed for you (open bars). Justifiy your predictions. 2. Use the graph below to predict what the results will look like if the null hypothesis is rejected. The total arousal counts in the control treatment at each interval is graphed for you (open bars). Justify your predictions. Null Supported Total Arousal counts Interval Null Rejected Total Arousal counts Interval NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 5 2 Credits: Title block photo by David A. Riggs (http://www.flickr.com/photos/driggs/6933593833/sizes/l/), cropped, used in accordance with CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0/). Figure 1 photo by Kevin Wenner/Pennsylvania Game Commision (http://www. portal.state.pa.us/portal/server.pt/document/901415/white-nose_kills_hundreds_of_bats_in_lackawanna_county_pdf ). Figure 2 photo courtesy of Ryan von Linden/New York Department of Environmental Conservation, http://www.flickr.com/photos/usfwshq/5765048289/sizes/l/in/ set-72157626818845664/, used in accordance with CC BY 2.0 (http://creativecommons.org/licenses/by/2.0/deed.en). Case copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Originally published February 6, 2014. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work. Part IV – Results Figure 3 (below) shows the real data from the study. There is no data for interval 4 bats that were exposed to the European P. destructans (gray bar) because all of the bats in that group died. Questions 1. How do your predictions compare with the experimental results? Be specific. 2. Do the results support or reject the null hypothesis? 3. If the European P. destructans is causing WNS in North America, how come European bats aren’t dying from the same disease? References U.S. Fish and Wildlife Service. 2012. White-Nose Syndrome. Available at: http://whitenosesyndrome.org/. Last accessed December 20, 2013. Warnecke, L., et al. 2012. Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome. PNAS Online Early Edition: http://www.pnas.org/cgi/ doi/10.1073/pnas.1200374109. Last accessed December 20, 2013. Figure 3. Changes in hibernation patterns in M. lucifugus following inoculation with North American P. destructans (NAGd), European P. destructans (EUGd), or the control serum. Interval Total Arousal counts

“No Bats in the Belfry” by Dechaine and Johnson Page 1 by Jennifer M. Dechaine1,2 and James E. Johnson1 1Department of Biological Sciences 2Department of Science Education Central Washington University, Ellensburg, WA NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Part I – The Basic Question Introduction Imagine going out for a brisk winter snowshoe and suddenly stumbling upon hundreds of bat carcasses littering the forest floor. Unfortunately, this unsettling sight has become all too common in the United States (Figure 1). White-nose syndrome (WNS), first discovered in 2006, has now spread to 20 states and has led to the deaths of over 5.5 million bats (as of January 2012). WNS is a disease caused by the fungus, Pseudogymnoascus destructans. Bats infected with WNS develop white fuzz on their noses (Figure 2, next page) and often exhibit unnatural behavior, such as flying outside during the winter when they should be hibernating. WNS affects at least six different bat species in the United States and quickly decimates bat populations (colony mortality is commonly greater than 90%). Scientists have predicted that if deaths continue at the current rate, several bat species will become locally extinct within 20 years. Bats provide natural pest control by eating harmful insects, such as crop pests and disease carrying insect species, and losing bat populations would have devastating consequences for the U.S. economy. Researchers have sprung into action to study how bats become infected with and transmit P. destructans, but a key component of this research is determining where the fungus came from in the first place. Some have suggested that it is an invasive species from a different country while others think it is a North American fungal species that has recently become better able to cause disease. In this case study, we examine the origin of P. destructans causing WNS in North America. Some Other Important Observations • WNS was first documented at four cave sites in New York State in 2006. • The fungus can be spread among bats by direct contact or spores can be transferred between caves by humans (on clothing) or other animals. • European strains of the fungus occur in low levels across Europe but have led to few bat deaths there. • Bats with WNS frequently awake during hibernation, causing them to use important fat reserves, leading to death. No Bats in the Belfry: The Origin of White- Nose Syndrome in Little Brown Bats Figure 1. Many bats dead in winter from white-nose syndrome. NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 2 Questions 1. What is the basic question of this study and why is it interesting? 2. What specific testable hypotheses can you develop to explain the observations and answer the basic question of this study? Write at least two alternative hypotheses. 3. What predictions about the effects of European strains of P. destructans on North American bats can you make if your hypotheses are correct? Write at least one prediction for each of your hypotheses. Figure 2. White fuzz on the muzzle of a little brown bat indicating infection by the disease. NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 3 Part II – The Hypothesis As discussed in Part I, researchers had preliminary data suggesting that the pathogen causing WNS is an invasive fungal species (P. destructans) brought to North America from Europe. They had also observed that P. destructans occurs on European bats but rarely causes their death. Preliminary research also suggested that one reason that bats have been dying from WNS is that the disorder arouses them from hibernation, causing the bats to waste fat reserves flying during the winter when food is not readily available. These observations led researchers to speculate that European P. destructans will affect North American bat hibernation at least as severely as does North American P. destructans (Warnecke et al. 2012). Questions 1. Explicitly state the researchers’ null (H0 ) and alternative hypotheses (HA) for this study. 2. Describe an experiment you could use to differentiate between these hypotheses (H0 and HA). NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 4 Part III – Experiments and Observations In 2010, Lisa Warnecke and colleagues (2012) isolated P. destructans fungal spores from Europe and North America. They collected 54 male little brown bats (Myotis lucifugus) from the wild and divided these bats equally into three treatment groups. • Group 1 was inoculated with the North American P. destructans spores (NAGd treatment). • Group 2 was inoculated with the European P. destructans spores (EUGd treatment). • Group 3 was inoculated using the inoculation serum with no spores (Control treatment). All three groups were put into separate dark chambers that simulated the environmental conditions of a cave. All bats began hibernating within the first week of the study. The researchers used infrared cameras to examine the bats’ hibernation over four consecutive intervals of 26 days each. They then used the cameras to determine the total number of times a bat was aroused from hibernation during each interval. Questions 1. Use the graph below to predict what the results will look like if the null hypothesis is supported. The total arousal counts in the control treatment at each interval is graphed for you (open bars). Justifiy your predictions. 2. Use the graph below to predict what the results will look like if the null hypothesis is rejected. The total arousal counts in the control treatment at each interval is graphed for you (open bars). Justify your predictions. Null Supported Total Arousal counts Interval Null Rejected Total Arousal counts Interval NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE “No Bats in the Belfry” by Dechaine and Johnson Page 5 2 Credits: Title block photo by David A. Riggs (http://www.flickr.com/photos/driggs/6933593833/sizes/l/), cropped, used in accordance with CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0/). Figure 1 photo by Kevin Wenner/Pennsylvania Game Commision (http://www. portal.state.pa.us/portal/server.pt/document/901415/white-nose_kills_hundreds_of_bats_in_lackawanna_county_pdf ). Figure 2 photo courtesy of Ryan von Linden/New York Department of Environmental Conservation, http://www.flickr.com/photos/usfwshq/5765048289/sizes/l/in/ set-72157626818845664/, used in accordance with CC BY 2.0 (http://creativecommons.org/licenses/by/2.0/deed.en). Case copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Originally published February 6, 2014. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work. Part IV – Results Figure 3 (below) shows the real data from the study. There is no data for interval 4 bats that were exposed to the European P. destructans (gray bar) because all of the bats in that group died. Questions 1. How do your predictions compare with the experimental results? Be specific. 2. Do the results support or reject the null hypothesis? 3. If the European P. destructans is causing WNS in North America, how come European bats aren’t dying from the same disease? References U.S. Fish and Wildlife Service. 2012. White-Nose Syndrome. Available at: http://whitenosesyndrome.org/. Last accessed December 20, 2013. Warnecke, L., et al. 2012. Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome. PNAS Online Early Edition: http://www.pnas.org/cgi/ doi/10.1073/pnas.1200374109. Last accessed December 20, 2013. Figure 3. Changes in hibernation patterns in M. lucifugus following inoculation with North American P. destructans (NAGd), European P. destructans (EUGd), or the control serum. Interval Total Arousal counts

checkyourstudy.com Whatsapp +919911743277
1. Develop a thought experiment that attempts to uncover hidden assumptions about human freedom. 2. Find a paragraph from a book, magazine, ect. First, tell whether there are claims in the paragraph. If there are, identify the types of claims (descriptive, normative, a priori, a posteriori) in the paragraph

1. Develop a thought experiment that attempts to uncover hidden assumptions about human freedom. 2. Find a paragraph from a book, magazine, ect. First, tell whether there are claims in the paragraph. If there are, identify the types of claims (descriptive, normative, a priori, a posteriori) in the paragraph

Let us think of a thought experiment that wants to … Read More...
In the article, “The Moral Person” it talks about Lawrence Kohlberg’s stages of moral development. Briefly explain the 3 Conventional levels (pre-conventional, conventional, and post-conventional). How may these stages impact one’s ethics? Think about how culture or the social environment affects our framework for coming up with any moral or ethical answer. (Hei Lam Kwan) In the article, they talked about a push for a “global ethic” or “one world”. Do you think this is possible? Besides the Golden Rule are there any other examples of shared ethics around the world? (Nicole Thompson) The article explained that often people know the distinction between right and wrong, but still do the wrong thing. If people know what is morally right, why do they act in ways that are morally wrong? (Nicole Thompson) In McLaren’s reading, he gives us a description on an idea of personhood to help us understand a moral person. He mentions a quote from the philosopher, Sarvepalli Rhadakrishnan that caught my interest. He says, “The self is not an object which we can find in knowledge, for it is the very condition of knowledge. It is different from all objects, the body, the senses, the empirical self itself (36)”. In your opinion, what exactly does he mean by stating that? Does thinking of yourself this way help you morally? (Maggy Ergun) Video: In the video, Damon Horowitz talks about the different approaches to figuring out what is right and what is wrong. Some of them included Plato, who believed that he could uncover the “truths about Justice”, Aristotle, who thought that people should use their current knowledge to make the right decision of here and now to their best ability, and Utilitarianism, who thought it was about measuring out the options to see which one had the most benefit for the greatest amount of people. Which approach do you think is best? Would you suggest another approach? (Nicole Thompson) Damon Horowitz explains the huge power we have and that is knowledge and data we receive from technology. With all this power in our hands, you can have any information you would like to obtain whether it’s on an object or human being. And as technology keeps rising, the more advanced it keeps getting. When it comes to privacy and dignity, do you think it is fair for one another to have this huge power on us? Will this be better for our future or worse? (Maggy Ergun) Horowitz describes how we rely more on our smart devices then actual moral thinking. (Mobile operating system then moral operating system) If we were to create a moral operating system, do you think that will help provoke people from making bad/evil decisions and guide us to better? Or do those bad decisions just come instantly without much thought? (Maggy Ergun) In the video it states, “what we need is a moral operating system.” What are the possible flaws in relying on a machine/software for answering ethical problems? Discuss and list at least one problem we may encounter from relying on such a system for an ethical solution. (Hei Lam Kwan) Reviewing the answers to the previous questions given, do you think there is only one right answer to any ethical question and why? (Hei Lam Kwan) http://www.ted.com/talks/damon_horowitz?language=en this is the video

In the article, “The Moral Person” it talks about Lawrence Kohlberg’s stages of moral development. Briefly explain the 3 Conventional levels (pre-conventional, conventional, and post-conventional). How may these stages impact one’s ethics? Think about how culture or the social environment affects our framework for coming up with any moral or ethical answer. (Hei Lam Kwan) In the article, they talked about a push for a “global ethic” or “one world”. Do you think this is possible? Besides the Golden Rule are there any other examples of shared ethics around the world? (Nicole Thompson) The article explained that often people know the distinction between right and wrong, but still do the wrong thing. If people know what is morally right, why do they act in ways that are morally wrong? (Nicole Thompson) In McLaren’s reading, he gives us a description on an idea of personhood to help us understand a moral person. He mentions a quote from the philosopher, Sarvepalli Rhadakrishnan that caught my interest. He says, “The self is not an object which we can find in knowledge, for it is the very condition of knowledge. It is different from all objects, the body, the senses, the empirical self itself (36)”. In your opinion, what exactly does he mean by stating that? Does thinking of yourself this way help you morally? (Maggy Ergun) Video: In the video, Damon Horowitz talks about the different approaches to figuring out what is right and what is wrong. Some of them included Plato, who believed that he could uncover the “truths about Justice”, Aristotle, who thought that people should use their current knowledge to make the right decision of here and now to their best ability, and Utilitarianism, who thought it was about measuring out the options to see which one had the most benefit for the greatest amount of people. Which approach do you think is best? Would you suggest another approach? (Nicole Thompson) Damon Horowitz explains the huge power we have and that is knowledge and data we receive from technology. With all this power in our hands, you can have any information you would like to obtain whether it’s on an object or human being. And as technology keeps rising, the more advanced it keeps getting. When it comes to privacy and dignity, do you think it is fair for one another to have this huge power on us? Will this be better for our future or worse? (Maggy Ergun) Horowitz describes how we rely more on our smart devices then actual moral thinking. (Mobile operating system then moral operating system) If we were to create a moral operating system, do you think that will help provoke people from making bad/evil decisions and guide us to better? Or do those bad decisions just come instantly without much thought? (Maggy Ergun) In the video it states, “what we need is a moral operating system.” What are the possible flaws in relying on a machine/software for answering ethical problems? Discuss and list at least one problem we may encounter from relying on such a system for an ethical solution. (Hei Lam Kwan) Reviewing the answers to the previous questions given, do you think there is only one right answer to any ethical question and why? (Hei Lam Kwan) http://www.ted.com/talks/damon_horowitz?language=en this is the video

info@checkyourstudy.com
BI 102 Lab 1 Writing Assignment How did the different concentrations of sucrose impact osmotic rate? This assignment requires you to evaluate a hypothesis and communicate the results of your experiment on the rate of osmosis into sucrose solutions of varying concentrations. The questions below are meant to guide you to reporting the key findings of your experiment and help you think through how to explain the findings and draw conclusions from them in a scientific manner. ASSIGNMENT: Please respond to the following questions to complete your laboratory write up. For this assignment you will only focus on the osmosis of water into sucrose concentrations of varying concentration. Make sure that your write up is accurate, and clearly written so that it is easily readable. A grading rubric is provided on the second page of this assignment. To earn full points on your write up, you must provide answers that align to the “meets” column of your grading rubric as well as meeting all “Quality of Writing and Mechanics” elements described in the rubric. There are also some tips on pages 3-4 of this assignment to help you succeed. FORMAT: • Type your responses, using 1.5 or double spacing. • Include the section headings (Hypothesis, Results, Analysis) and question number (example: 1, 2, 3, etc) in your answers but do not rewrite the question. • Graphs may be made with a computer program (example: Microsoft excel, Mac numbers, etc) or may be neatly produced with a ruler on graphing paper. • Print out the cover sheet on page 2 of this assignment, read and sign the academic honesty statement, and submit it with your write up. Your instructor WILL NOT accept a write up without the signed cover sheet. DUE DATE: Your write up is due at the beginning of class next week. Late assignments will have 1 point deducted per day up to 5 days, at which point the assignment will be assigned 0 points. Hypothesis and Prediction – Part 1 of Rubric 1. What did you think was going to happen in this experiment and why? You may find it helpful to state your answers to these questions as an “if-then” hypothesis-prediction. Be sure you have included a biological rationale that explains WHY you made this hypothesis/prediction. (You worked on this in question 2 on page 10 of this lab activity) Results – Part 2 of Rubric 2. How did the different concentrations of sucrose impact osmotic rate? Answer this question by creating a line graph that shows the results of your experiment. If you need assistance building a graph, there is a Guide to Graphing resource available on your Moodle lab course site. Analysis- Part 3 of Rubric 3. Explain why you think that the results shown in your graph support or refute your hypothesis (remember we never “prove” anything in science). Consider all your data and the overall data pattern as you answer this question. Don’t ignore unusual data that may not seem to fit into a specific patterns (“outliers”). Explain what you think might be behind these unusual data points. 4. What is the biological significance of your results? What biological concepts explain completely why these events happened in the experiment? How do these results help you understand the biology of the cell and how materials move back and forth across the cell membrane? (A hint: refer back to questions 1A-1F on page 10 of this lab activity). Think about giving a specific example. References- Mechanics Checklist 5. Provide at least one full citation (make sure you include an in-text citation that pinpoints where you used this resource) for a resource you made use of in performing the experiment, understanding the concepts and writing this assignment. (Perhaps your lab manual? Your textbook? A website?) If you used more than one resource, you need to cite each one! If you need help with citations, a Guide to Citing References is available on your Moodle lab course site. Please print out and submit this cover sheet with your lab writeup! Lab Writeup Assignment (1) Assessment Rubric-­‐ 10 points total Name: ________________________________________ Element Misses (1 point) Approaches (2 points) Meets (3 points) Hypothesis Clarity/Specificity Testability Rationale ___Hypothesis is unclear and hardto- understand ___Hypothesis is not testable ___No biological rationale for hypothesis or rationale is fully inaccurate ___Hypothesis included is clearly stated, but not specific or lacks specific details __Hypothesis is testable, but not in a feasible way in this lab ___Some foundation for hypothesis, but based in part on biological inaccuracy ___Hypothesis included is clearly stated and very specific ___Hypothesis is testable and could be tested within lab parameters ___Rationale for hypothesis is grounded in accurate biological information Graph Title Axes Variables Key Graph clarity Data accuracy ___Graph lacks a title ___Axes are not labeled ___Variables not addressed in graph ___No key or way to tell data points apart ___Graph is hard to read and comparisons cannot be made: Inappropriate graph type or use of scale ___Data graphed is inaccurate or does not relate to experiment ___Graph has a title that is not very descriptive ___Axes are either unlabeled, or units are unclear or wrong ___Variables addressed in graph, but not on correct axes ___Key included, but is hard to understand ___Graph is somewhat readable, comparisons can be made with difficulty: Appropriate graph type, but not scaled well ___Data graphed is partially accurate; some data is missing ___Graph has a concise, descriptive title ___Axes are labeled, including clarification of units used ___Variables on correct axes ___A clear, easy-to-use key to data points is included ___Graph is clearly readable and comparisons between treatments are easy to make: Graph type and scale are appropriate to data ___Data graphed is accurate and includes all relevant data, including controls (if needed) Analysis Hypothesis Scientific language Data addressed Explanation ___Hypothesis is not addressed ___Hypothesis is described using language like proven, true, or right ___No explanations for data patterns observed in graph or data does not support conclusions. ___No biological explanation for data trends or explanations are completely inaccurate ___Hypothesis is mentioned, but not linked well to data ___Hypothesis is not consistently described as supported or refuted ___Some data considered in conclusions but other data is ignored. Any unusual “outliers” are ignored ___Explanations include minimal or some inaccurate biological concepts ___Hypothesis is evaluated based upon data ___Hypothesis is consistently described as supported or refuted ___All data collected is considered and addressed by conclusions, including presence of outliers, ___Explanations include relevant and accurate biological concepts Quality of Writing and Mechanics: Worth 1 point. Writeup should meet all of the following criteria! Yes No ☐ ☐ Write up includes your name, the date, and your lab section ☐ ☐ Write up is free from spelling and grammatical errors (make sure you proofread!!) ☐ ☐ Write up is clear and easy-to-understand ☐ ☐ Write up includes full citation for at least one reference with corresponding in-text citation ☐ ☐ All portions of write up are clearly labeled, and question numbers are included Plagiarism refers to the use of original work, ideas, or text that are not your own. This includes cut-and-paste from websites, copying directly from texts, and copying the work of others, including fellow students. Telling someone your answers to the questions (including telling someone how to make their graph, question #2), or asking for the answers to any question, is cheating. (Asking someone how to make the graph for this assignment is NOT the same as asking for help learning excel or some other software). All forms of cheating, including plagiarism and copying of work will result in an immediate zero for the exam, quiz, or assignment. In the case of copying, all parties involved in the unethical behavior will earn zeros. Cheating students will be referred to the Student Conduct Committee for further action. You also have the right to appeal to the Student Conduct Committee. I have read and understand the plagiarism statement. ____________________________________________________ Signature Guidelines for Good Quality Scientific Reports Hypothesis and Prediction: The hypothesis is a tentative explanation for the phenomenon. Remember that: • A good hypothesis and prediction is testable (and should be testable under the conditions of our lab environment; For example, if your hypothesis requires shooting a rocket into space, then its not really testable under our laboratory conditions). • Your explanation can be ruled out through testing, or falsified. • A good hypothesis and prediction is detailed and specific in what it is testing. • A good hypothesis provides a rationale or explanation for why you think your prediction is reasonable and this rationale is based on what we know about biology. • A good prediction is specific and can be tested with a specific experiment. Examples*: I think that diet soda will float and regular soda will sink. {This hypothesis misses the goal. It is not specific as we don’t know where the sodas are floating and sinking, and it does not provide any explanation to explain why the hypothesis makes sense} Because diet soda does not contain sugar and regular soda does, the diet soda will float in a bucket of water, while regular soda will sink. {This hypothesis approaches the goal. It is more specific about the conditions, and it provides a partial explanation about why the hypothesis makes sense, but the connection between sugar and sinking is unclear} If diet soda does not contain sugar, then its density (mass/volume) is lower than that of regular soda which does contain sugar, and so diet soda will float in a bucket of water while regular soda sinks. {This hypothesis meets the goal. It is specific and the rationale- sugar affects density and density is what determines floating or sinking in water- is clearly articulated} *Note that these examples are for different experiments and investigations and NOT about your osmosis lab. They are provided only to help you think about what you need to include in your write up. Graph: The graph is a visual representation of the data you gathered while testing your hypothesis. Remember that: • A graph needs a concise title that clearly describes the data that it is showing. • Data must be put on the correct axes of the graph. In general, the data you collected (representing what you are trying to find out about) goes on the vertical (Y) axis. The supporting data that that describes how, when or under what conditions you collected your data goes on the horizontal (X) axis. (For this reason time nearly always goes on the X-axis). • Axes must be labeled, including the units in which data were recorded • Data points should be clearly marked and identified; a key is helpful if more than one group of data is included in the graph. • The scale of a graph is important. It should be consistent (there should be no change in the units or increments on a single axis) and appropriate to the data you collected Examples: {This graph misses the goal. There is no title, nor is there a key to help distinguish what the data points mean. The scale is too large- from 0 to 100 with an increment of 50, when the maximum number in the graph is 25- and makes it hard to interpret this graph. The x-axis is labeled, but without units (the months) and the y-axis has units, but the label is incomplete- number of what?} {This graph meets the goal. There is a descriptive title, and all of the axes are clearly labeled with units. There is a key so that we can distinguish what each set of data points represent. The dependent variable (number of individuals) is correctly placed on the y-axis with the independent variable of time placed on the x-axis. The scale of 0-30 is appropriate to the data, with each line on the x-axis representing an increment of 5.} 0 50 100 Number Month 0 5 10 15 20 25 30 March April May June July Number of individuals Month (2011) Population size of three different madtom catiCish in the Marais de Cygnes River in Spring/Summer 2011 Brindled madtom Neosho madtom Slender madtom Analysis: You need to evaluate your hypothesis based on the data patterns shown by your graph. Remember that: • You use data to determine support or refute your hypothesis. It is only possible to support a hypothesis, not to “prove” one (that would require testing every possible permutation and combination of factors). Your evaluation of your hypothesis should not be contradicted by the pattern shown by your data. • Refer back to the prediction you made as part of your hypothesis and use your data to justify your decision to support or refute your hypothesis. • In the “if” part of your hypothesis you should have provided a rationale, or explanation for the prediction you made in your hypothesis (“then” part of hypothesis”). Use this to help you explain why you think you observed the specific pattern of data revealed in your graph. • You should consider all of the data you collected in examining the support (or lack of support for your hypothesis). If there are unusual data points or “outliers” that don’t seem to fit the general pattern in your graph, explain what you think those mean. Examples: I was right. Diet Pepsi floated and so did Apricot Nectar. Regular Pepsi sank. Obviously the regular Pepsi was heavier. This helps us understand the concept of density, which is a really important one. {This analysis misses the goal. The hypothesis isn’t actually mentioned and the data is only briefly described. There is no explanation of the importance of the Apricot Nectar results. Finally, there is no connection to how these results help understand density or why it is biologically important} I hypothesized that diet soda would float, and all three cans of diet Pepsi did float while the regular Pepsi sank. This supports my hypothesis. Both types of Pepsi were 8.5 fluid ounces in volume, but the regular Pepsi also contained 16 grams of sugar. This means that the regular Pepsi had 16 more grams of mass provided by the sugar in the same amount of volume. This would lead to an increase in density, which explains why the regular soda cans sank. When we put in a can of Apricot Nectar, which had 19 grams of sugar, it floated. This was unexpected, but I think it is explained by the fact that an Apricot Nectar can had a volume of 7 fluid ounces, but the dimensions of the can are the same as that of a Pepsi can. A same-sized can with less liquid probably has an air space that helped it float. The results of this experiment help us understand how the air bladder of a fish, which creates an air space inside the fish, helps it float in the water and also how seaweeds and other living things with air spaces or other factors that decrease their density keep from sinking to the bottom of the water. {This analysis meets the goal. It clearly ties the hypothesis to the results and outlines what they mean. It describes how the results support the hypothesis, but also explains a possible reason behind the unusual results of the Apricot Nectar. Finally, there is a link to how this experiment helps us understand biology}

BI 102 Lab 1 Writing Assignment How did the different concentrations of sucrose impact osmotic rate? This assignment requires you to evaluate a hypothesis and communicate the results of your experiment on the rate of osmosis into sucrose solutions of varying concentrations. The questions below are meant to guide you to reporting the key findings of your experiment and help you think through how to explain the findings and draw conclusions from them in a scientific manner. ASSIGNMENT: Please respond to the following questions to complete your laboratory write up. For this assignment you will only focus on the osmosis of water into sucrose concentrations of varying concentration. Make sure that your write up is accurate, and clearly written so that it is easily readable. A grading rubric is provided on the second page of this assignment. To earn full points on your write up, you must provide answers that align to the “meets” column of your grading rubric as well as meeting all “Quality of Writing and Mechanics” elements described in the rubric. There are also some tips on pages 3-4 of this assignment to help you succeed. FORMAT: • Type your responses, using 1.5 or double spacing. • Include the section headings (Hypothesis, Results, Analysis) and question number (example: 1, 2, 3, etc) in your answers but do not rewrite the question. • Graphs may be made with a computer program (example: Microsoft excel, Mac numbers, etc) or may be neatly produced with a ruler on graphing paper. • Print out the cover sheet on page 2 of this assignment, read and sign the academic honesty statement, and submit it with your write up. Your instructor WILL NOT accept a write up without the signed cover sheet. DUE DATE: Your write up is due at the beginning of class next week. Late assignments will have 1 point deducted per day up to 5 days, at which point the assignment will be assigned 0 points. Hypothesis and Prediction – Part 1 of Rubric 1. What did you think was going to happen in this experiment and why? You may find it helpful to state your answers to these questions as an “if-then” hypothesis-prediction. Be sure you have included a biological rationale that explains WHY you made this hypothesis/prediction. (You worked on this in question 2 on page 10 of this lab activity) Results – Part 2 of Rubric 2. How did the different concentrations of sucrose impact osmotic rate? Answer this question by creating a line graph that shows the results of your experiment. If you need assistance building a graph, there is a Guide to Graphing resource available on your Moodle lab course site. Analysis- Part 3 of Rubric 3. Explain why you think that the results shown in your graph support or refute your hypothesis (remember we never “prove” anything in science). Consider all your data and the overall data pattern as you answer this question. Don’t ignore unusual data that may not seem to fit into a specific patterns (“outliers”). Explain what you think might be behind these unusual data points. 4. What is the biological significance of your results? What biological concepts explain completely why these events happened in the experiment? How do these results help you understand the biology of the cell and how materials move back and forth across the cell membrane? (A hint: refer back to questions 1A-1F on page 10 of this lab activity). Think about giving a specific example. References- Mechanics Checklist 5. Provide at least one full citation (make sure you include an in-text citation that pinpoints where you used this resource) for a resource you made use of in performing the experiment, understanding the concepts and writing this assignment. (Perhaps your lab manual? Your textbook? A website?) If you used more than one resource, you need to cite each one! If you need help with citations, a Guide to Citing References is available on your Moodle lab course site. Please print out and submit this cover sheet with your lab writeup! Lab Writeup Assignment (1) Assessment Rubric-­‐ 10 points total Name: ________________________________________ Element Misses (1 point) Approaches (2 points) Meets (3 points) Hypothesis Clarity/Specificity Testability Rationale ___Hypothesis is unclear and hardto- understand ___Hypothesis is not testable ___No biological rationale for hypothesis or rationale is fully inaccurate ___Hypothesis included is clearly stated, but not specific or lacks specific details __Hypothesis is testable, but not in a feasible way in this lab ___Some foundation for hypothesis, but based in part on biological inaccuracy ___Hypothesis included is clearly stated and very specific ___Hypothesis is testable and could be tested within lab parameters ___Rationale for hypothesis is grounded in accurate biological information Graph Title Axes Variables Key Graph clarity Data accuracy ___Graph lacks a title ___Axes are not labeled ___Variables not addressed in graph ___No key or way to tell data points apart ___Graph is hard to read and comparisons cannot be made: Inappropriate graph type or use of scale ___Data graphed is inaccurate or does not relate to experiment ___Graph has a title that is not very descriptive ___Axes are either unlabeled, or units are unclear or wrong ___Variables addressed in graph, but not on correct axes ___Key included, but is hard to understand ___Graph is somewhat readable, comparisons can be made with difficulty: Appropriate graph type, but not scaled well ___Data graphed is partially accurate; some data is missing ___Graph has a concise, descriptive title ___Axes are labeled, including clarification of units used ___Variables on correct axes ___A clear, easy-to-use key to data points is included ___Graph is clearly readable and comparisons between treatments are easy to make: Graph type and scale are appropriate to data ___Data graphed is accurate and includes all relevant data, including controls (if needed) Analysis Hypothesis Scientific language Data addressed Explanation ___Hypothesis is not addressed ___Hypothesis is described using language like proven, true, or right ___No explanations for data patterns observed in graph or data does not support conclusions. ___No biological explanation for data trends or explanations are completely inaccurate ___Hypothesis is mentioned, but not linked well to data ___Hypothesis is not consistently described as supported or refuted ___Some data considered in conclusions but other data is ignored. Any unusual “outliers” are ignored ___Explanations include minimal or some inaccurate biological concepts ___Hypothesis is evaluated based upon data ___Hypothesis is consistently described as supported or refuted ___All data collected is considered and addressed by conclusions, including presence of outliers, ___Explanations include relevant and accurate biological concepts Quality of Writing and Mechanics: Worth 1 point. Writeup should meet all of the following criteria! Yes No ☐ ☐ Write up includes your name, the date, and your lab section ☐ ☐ Write up is free from spelling and grammatical errors (make sure you proofread!!) ☐ ☐ Write up is clear and easy-to-understand ☐ ☐ Write up includes full citation for at least one reference with corresponding in-text citation ☐ ☐ All portions of write up are clearly labeled, and question numbers are included Plagiarism refers to the use of original work, ideas, or text that are not your own. This includes cut-and-paste from websites, copying directly from texts, and copying the work of others, including fellow students. Telling someone your answers to the questions (including telling someone how to make their graph, question #2), or asking for the answers to any question, is cheating. (Asking someone how to make the graph for this assignment is NOT the same as asking for help learning excel or some other software). All forms of cheating, including plagiarism and copying of work will result in an immediate zero for the exam, quiz, or assignment. In the case of copying, all parties involved in the unethical behavior will earn zeros. Cheating students will be referred to the Student Conduct Committee for further action. You also have the right to appeal to the Student Conduct Committee. I have read and understand the plagiarism statement. ____________________________________________________ Signature Guidelines for Good Quality Scientific Reports Hypothesis and Prediction: The hypothesis is a tentative explanation for the phenomenon. Remember that: • A good hypothesis and prediction is testable (and should be testable under the conditions of our lab environment; For example, if your hypothesis requires shooting a rocket into space, then its not really testable under our laboratory conditions). • Your explanation can be ruled out through testing, or falsified. • A good hypothesis and prediction is detailed and specific in what it is testing. • A good hypothesis provides a rationale or explanation for why you think your prediction is reasonable and this rationale is based on what we know about biology. • A good prediction is specific and can be tested with a specific experiment. Examples*: I think that diet soda will float and regular soda will sink. {This hypothesis misses the goal. It is not specific as we don’t know where the sodas are floating and sinking, and it does not provide any explanation to explain why the hypothesis makes sense} Because diet soda does not contain sugar and regular soda does, the diet soda will float in a bucket of water, while regular soda will sink. {This hypothesis approaches the goal. It is more specific about the conditions, and it provides a partial explanation about why the hypothesis makes sense, but the connection between sugar and sinking is unclear} If diet soda does not contain sugar, then its density (mass/volume) is lower than that of regular soda which does contain sugar, and so diet soda will float in a bucket of water while regular soda sinks. {This hypothesis meets the goal. It is specific and the rationale- sugar affects density and density is what determines floating or sinking in water- is clearly articulated} *Note that these examples are for different experiments and investigations and NOT about your osmosis lab. They are provided only to help you think about what you need to include in your write up. Graph: The graph is a visual representation of the data you gathered while testing your hypothesis. Remember that: • A graph needs a concise title that clearly describes the data that it is showing. • Data must be put on the correct axes of the graph. In general, the data you collected (representing what you are trying to find out about) goes on the vertical (Y) axis. The supporting data that that describes how, when or under what conditions you collected your data goes on the horizontal (X) axis. (For this reason time nearly always goes on the X-axis). • Axes must be labeled, including the units in which data were recorded • Data points should be clearly marked and identified; a key is helpful if more than one group of data is included in the graph. • The scale of a graph is important. It should be consistent (there should be no change in the units or increments on a single axis) and appropriate to the data you collected Examples: {This graph misses the goal. There is no title, nor is there a key to help distinguish what the data points mean. The scale is too large- from 0 to 100 with an increment of 50, when the maximum number in the graph is 25- and makes it hard to interpret this graph. The x-axis is labeled, but without units (the months) and the y-axis has units, but the label is incomplete- number of what?} {This graph meets the goal. There is a descriptive title, and all of the axes are clearly labeled with units. There is a key so that we can distinguish what each set of data points represent. The dependent variable (number of individuals) is correctly placed on the y-axis with the independent variable of time placed on the x-axis. The scale of 0-30 is appropriate to the data, with each line on the x-axis representing an increment of 5.} 0 50 100 Number Month 0 5 10 15 20 25 30 March April May June July Number of individuals Month (2011) Population size of three different madtom catiCish in the Marais de Cygnes River in Spring/Summer 2011 Brindled madtom Neosho madtom Slender madtom Analysis: You need to evaluate your hypothesis based on the data patterns shown by your graph. Remember that: • You use data to determine support or refute your hypothesis. It is only possible to support a hypothesis, not to “prove” one (that would require testing every possible permutation and combination of factors). Your evaluation of your hypothesis should not be contradicted by the pattern shown by your data. • Refer back to the prediction you made as part of your hypothesis and use your data to justify your decision to support or refute your hypothesis. • In the “if” part of your hypothesis you should have provided a rationale, or explanation for the prediction you made in your hypothesis (“then” part of hypothesis”). Use this to help you explain why you think you observed the specific pattern of data revealed in your graph. • You should consider all of the data you collected in examining the support (or lack of support for your hypothesis). If there are unusual data points or “outliers” that don’t seem to fit the general pattern in your graph, explain what you think those mean. Examples: I was right. Diet Pepsi floated and so did Apricot Nectar. Regular Pepsi sank. Obviously the regular Pepsi was heavier. This helps us understand the concept of density, which is a really important one. {This analysis misses the goal. The hypothesis isn’t actually mentioned and the data is only briefly described. There is no explanation of the importance of the Apricot Nectar results. Finally, there is no connection to how these results help understand density or why it is biologically important} I hypothesized that diet soda would float, and all three cans of diet Pepsi did float while the regular Pepsi sank. This supports my hypothesis. Both types of Pepsi were 8.5 fluid ounces in volume, but the regular Pepsi also contained 16 grams of sugar. This means that the regular Pepsi had 16 more grams of mass provided by the sugar in the same amount of volume. This would lead to an increase in density, which explains why the regular soda cans sank. When we put in a can of Apricot Nectar, which had 19 grams of sugar, it floated. This was unexpected, but I think it is explained by the fact that an Apricot Nectar can had a volume of 7 fluid ounces, but the dimensions of the can are the same as that of a Pepsi can. A same-sized can with less liquid probably has an air space that helped it float. The results of this experiment help us understand how the air bladder of a fish, which creates an air space inside the fish, helps it float in the water and also how seaweeds and other living things with air spaces or other factors that decrease their density keep from sinking to the bottom of the water. {This analysis meets the goal. It clearly ties the hypothesis to the results and outlines what they mean. It describes how the results support the hypothesis, but also explains a possible reason behind the unusual results of the Apricot Nectar. Finally, there is a link to how this experiment helps us understand biology}

info@checkyourstudy.com Whatsapp +919911743277
ENGR 2010 (Section 02) – Assignment 7 Due: Wednesday November 25th, 11:59 pm Points: 20 Prof. Lei Reading: Sections 6.2-6.3 of Nilsson and Riedel, Electric Circuits, 9th Edition Submit electronic solutions (i.e. using Microsoft Word or a scanned copy of your written work) to the following problems on Blackboard. To receive credit, you must show work indicating how you arrived at each final answer. Problem 1 Consider the RC circuit on the right. and suppose that Vs(t) is a time-varying voltage input shown at the bottom. a) Suppose VC(0) = 0V. Plot VR(t) and VC(t) from 0ms to 300ms. Show your work in obtaining VR(t) and VC(t). b) Suppose the capacitance value is changed to 2μF, and VC(0) = 0V. Plot VR(t) and VC(t) from 0ms to 300ms. Show your work in obtaining VR(t) and VC(t). c) Explain how VC(t) qualitatively compares with Vs(t), and how VR(t) qualitatively compares with Vs(t). d) Explain how the capacitance value affects VC(t). t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms Note: Capacitors are often used to protect against sudden changes in a voltage value, which could damage electronic components. Here, Vs(t) undergoes many sudden changes, but VC(t) undergoes less change. Problem 2 Using PSpice, perform two transient analysis simulations – one for the circuit in part (a), and one for the circuit in part(b) of problem 1 – to verify that your plots in problem 1 are correct. For each simulation, plot the traces for VR(t) and VC(t). Hint: You may need to perform arithmetic operations between simulation traces. Take a screenshot of your constructed circuits and the simulation traces for VR(t) and VC(t), which you will submit onto Blackboard. t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms 1 uF or 2 uF Problem 3 Consider the Resistor-Diode circuit on the right, and suppose that Vs(t) is a time-varying voltage input shown at the bottom. Suppose that for the diode to turn on, it needs 0.7V between the positive and negative terminals. a) Plot VR(t) and VD(t) from 0ms to 300ms b) Explain how VD(t) qualitatively compares with Vs(t), and how VR(t) qualitatively compares with Vs(t). t Vs(t) 1V -1V 50ms 100ms 0ms 150ms 200ms 250ms 300ms + – Vs(t) 100000 Ohms + – VD(t) + – VR(t) Problem 4 Using PSpice, perform a transient analysis simulation for the circuit in problem 3 – to verify that your plots in problem 3 are correct. For the simulation, plot the traces for VR(t) and VD(t). To create the diode in PSpice, use the Dbreak component. After placing the component on the page, highlight the component, and edit the Pspice model (Edit -> PSpice Model) and set Rs to 0. Hint: You may need to perform arithmetic operations between simulation traces. Take a screenshot of your constructed circuit and the simulation traces for VR(t) and VD(t), which you will submit onto Blackboard. Note that your simulation trace plots may not be exactly the same as those from Problem 3, since the PSpice diode model has a turn-on voltage that’s not exactly 0.7V. t Vs(t) 1V -1V 50ms 100ms 0ms 150ms 200ms 250ms 300ms + – Vs(t) 100000 Ohms + – VD(t) + – VR(t) Problem 5 (Bonus: 5 points) In the circuit from problem 1 (shown on the right), write several sentences to explain why VC(t) is often referred to as the “low-pass filtered” output, and VR(t) is often referred to as the “high-pass filtered” output. You will need to look up the definitions for “low-pass” and “high-pass” filters. Examining your plots for VC(t) and VR(t) will help. t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms

ENGR 2010 (Section 02) – Assignment 7 Due: Wednesday November 25th, 11:59 pm Points: 20 Prof. Lei Reading: Sections 6.2-6.3 of Nilsson and Riedel, Electric Circuits, 9th Edition Submit electronic solutions (i.e. using Microsoft Word or a scanned copy of your written work) to the following problems on Blackboard. To receive credit, you must show work indicating how you arrived at each final answer. Problem 1 Consider the RC circuit on the right. and suppose that Vs(t) is a time-varying voltage input shown at the bottom. a) Suppose VC(0) = 0V. Plot VR(t) and VC(t) from 0ms to 300ms. Show your work in obtaining VR(t) and VC(t). b) Suppose the capacitance value is changed to 2μF, and VC(0) = 0V. Plot VR(t) and VC(t) from 0ms to 300ms. Show your work in obtaining VR(t) and VC(t). c) Explain how VC(t) qualitatively compares with Vs(t), and how VR(t) qualitatively compares with Vs(t). d) Explain how the capacitance value affects VC(t). t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms Note: Capacitors are often used to protect against sudden changes in a voltage value, which could damage electronic components. Here, Vs(t) undergoes many sudden changes, but VC(t) undergoes less change. Problem 2 Using PSpice, perform two transient analysis simulations – one for the circuit in part (a), and one for the circuit in part(b) of problem 1 – to verify that your plots in problem 1 are correct. For each simulation, plot the traces for VR(t) and VC(t). Hint: You may need to perform arithmetic operations between simulation traces. Take a screenshot of your constructed circuits and the simulation traces for VR(t) and VC(t), which you will submit onto Blackboard. t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms 1 uF or 2 uF Problem 3 Consider the Resistor-Diode circuit on the right, and suppose that Vs(t) is a time-varying voltage input shown at the bottom. Suppose that for the diode to turn on, it needs 0.7V between the positive and negative terminals. a) Plot VR(t) and VD(t) from 0ms to 300ms b) Explain how VD(t) qualitatively compares with Vs(t), and how VR(t) qualitatively compares with Vs(t). t Vs(t) 1V -1V 50ms 100ms 0ms 150ms 200ms 250ms 300ms + – Vs(t) 100000 Ohms + – VD(t) + – VR(t) Problem 4 Using PSpice, perform a transient analysis simulation for the circuit in problem 3 – to verify that your plots in problem 3 are correct. For the simulation, plot the traces for VR(t) and VD(t). To create the diode in PSpice, use the Dbreak component. After placing the component on the page, highlight the component, and edit the Pspice model (Edit -> PSpice Model) and set Rs to 0. Hint: You may need to perform arithmetic operations between simulation traces. Take a screenshot of your constructed circuit and the simulation traces for VR(t) and VD(t), which you will submit onto Blackboard. Note that your simulation trace plots may not be exactly the same as those from Problem 3, since the PSpice diode model has a turn-on voltage that’s not exactly 0.7V. t Vs(t) 1V -1V 50ms 100ms 0ms 150ms 200ms 250ms 300ms + – Vs(t) 100000 Ohms + – VD(t) + – VR(t) Problem 5 (Bonus: 5 points) In the circuit from problem 1 (shown on the right), write several sentences to explain why VC(t) is often referred to as the “low-pass filtered” output, and VR(t) is often referred to as the “high-pass filtered” output. You will need to look up the definitions for “low-pass” and “high-pass” filters. Examining your plots for VC(t) and VR(t) will help. t Vs(t) 1V -1V 50ms 100ms 150ms 200ms 250ms + – Vs(t) 100000 Ohms 1 uF + – VC(t) + – VR(t) 0ms 300ms

No expert has answered this question yet. You can browse … Read More...