Describe the Voigt-Kelvin model with the aid of sketches. What are its strengths and limitations?

Describe the Voigt-Kelvin model with the aid of sketches. What are its strengths and limitations?

  For this model, the spring and dashpot are put … Read More...
Two wires #1 carries a current I, toward the top of the page and is held rigidly in place. wire #2 carries a current I to the left and is free to move. wire # 2 will experience a magnatic force which cause it to; 1) move down , 2) move up , 3) rotate clockwise , 4) rotate counterclockwise, 5) move right.

Two wires #1 carries a current I, toward the top of the page and is held rigidly in place. wire #2 carries a current I to the left and is free to move. wire # 2 will experience a magnatic force which cause it to; 1) move down , 2) move up , 3) rotate clockwise , 4) rotate counterclockwise, 5) move right.

Assignment 2 Conditional Probability, Bayes Theorem, and Random Variables Conditional Probability and Bayes’ Theorem Problems 1-14 from Problem Set on Conditional Probability and Bayes’ Theorem I am including all the question here so that there is no confusion. Q1. Pair of six sided dices are rolled and the outcome is noted: What is the sample space? What is the size of the sample space? Suppose all we are interested in is the sum of the two outcomes. What is the probability that the sum of the two is 6? 7? 8? (Note: This can be solved using both enumeration and conditional probability method). Here, it makes more sense to use the enumeration approach than conditional probability. It is, however, listed here to set the stage for Q5. What is the probability that the sum of the two is above 5 and the two numbers are equal? Express this question in terms of events A, B, and set operators. What is the probability that the sum of the two is above 5 or the two numbers are equal? Express this question in terms of events A, B, and set operators. Q2. If P(A)=0.4, P(B)=0.5 and P(A∩B)=0.3 What is the value of (a) P(A|B) and (b) P(B|A) Q3. At a fair, a vendor has 25 helium balloons on strings: 10 balloons are yellow, 8 are red, and 7 are green. A balloon is selected at random and sold. Given that the balloon sold is yellow, what is the probability that the next balloon selected at random is also yellow? Q4. A bowl contains seven blue chips and three red chips. Two chips are to be drawn at random and without replacement. What is the probability that the fist chip is a red chip and the second a blue? Express this question in terms of events A, B, and set operators and use conditional probability. Q5. Three six sided dices are rolled and the outcome is noted: What is the size of the sample space? What is the probability that the sum of the three numbers is 6? 13? 18? Solve using conditional probability How does the concept of conditional probability help? Q6. A grade school boy has 5 blue and four white marbles in his left pocket and four blue and five white marbles in his right pocket. If he transfers one marble at random from his left pocket to his right pocket, what is the probability of his then drawing a blue marble from his right pocket? Q7. In a certain factory, machine I, II, and III are all producing springs of the same length. Of their production, machines I, II, and III produce 2%, 1%, and 3% defective springs respectively. Of the total production of springs in the factory, machine I produces 35%, machine II produces 25%, and machine III produces 40%. If one spring is selected at random from the total springs produced in a day, what is the probability that it is defective? Given that the selected spring is defective, what is the probability that it was produced on machine III? Q8. Bowl B1 contains 2 white chips, bowl B2 contains 2 red chips, bowl B3 contains 2 white and 2 red chips, and Bowl B4 contains 3 white chips and 1 red chip. The probabilities of selecting bowl B1, B2, B3, and B4 are 1/2, 1/4, 1/8, and 1/8 respectively. A bowl is selected using these probabilities, and a chip is then drawn at random. Find P(W), the probability of drawing a white chip P(B1|W): the probability that bowl B1 was selected, given that a white chip was drawn. Q9. A pap smear is a screening procedure used to detect cervical cancer. For women with this cancer, there are about 16% false negative. For women without cervical cancer, there are about 19% false positive. In the US, there are about 8 women in 100,000 who have this cancer. What is the probability that a woman who has been tested positive actually has cervical cancer? Q10. There is a new diagnostic test for a disease that occurs in about 0.05% of the population. The test is not perfect but will detect a person with the disease 99% of the time. It will, however, say that a person without the disease has the disease about 3% of the time. A person is selected at random from the population and the test indicates that this person has the disease. What are the conditional probabilities that The person has the disease The person does not have the disease Q11. Consider two urns: the first contains two white and seven black balls, and the second contains five white and six black balls. We flip a fair coin and then draw a ball from the first urn or the second urn depending on whether the outcome was a head or a tails. What is the conditional probability that the outcome of the toss was heads given that a white ball was selected? Q12. In answering a question on a multiple-choice test a student either knows the answer or guesses. Let p be the probability that she knows the answer. Assume that a student who guesses at the answer will be correct with probability 1/m where m is the number of multiple choice alternatives. What is the conditional probability that a student knew the answer given that she answered it correctly? Q13. A laboratory blood test is 95% effective in detecting a certain disease when it is, in fact, present. However, the test also yields a “false positive” result for 1% of the healthy persons tested (i.e., if a healthy person is tested, then, with probability 0.01, the test result will imply that he has the disease.). If 0.5% of the population actually have the disease, what is the probability a person has the disease given that his test results are positive? Q14. An urn contains b black balls and r red balls. One of the balls is drawn at random, but when it is put back in the urn, c additional balls of the same color are put in it with it. Now suppose that we draw another ball. What is the probability that the first ball drawn was black given that the second ball drawn was red? Random Variables Q15. Suppose an experiment consists of tossing two six sided fair dice and observing the outcomes. What is the sample space? Let Y denote the sum of the two numbers that appear on the dice. Define Y to be a random variable. What are the values that the random variable Y can take? What does it mean if we say Y=7? What does it mean if I say that Y<7? Q16. Suppose an experiment consists of picking a sample of size n from a population of size N. Assume that n≪N. Also, assume that the population contains D defective parts and N-D non defective parts, where n<D≪N. What is the sample space? If we are interested in knowing the number (count) of defective parts in the sample space, describe how, the concept of a random variable could help. Define a random variable Y and describe what values the random variable Y can take? What does it mean if we say Y=5? Q17. Suppose an experiment consists of tossing two fair coins. Let Y denote the number of heads appearing. Define Y to be a random variable. What are the values that the random variable Y can take? What does it mean if we say Y=1? What are the probabilities associated with each outcome? What is the sum of the probabilities associated with all possible values that Y can take? Q18. A lot, consisting of 100 fuses, is inspected by the following procedure. Five fuses are chosen at random and tested: if all 5 fuses pass the inspection, the lot is accepted. Suppose that the lot contains 20 defective fuses. What is the probability of accepting the lot? Define the random variable, its purpose, and the formula/concept that you would use. Q19. In a small pond there are 50 fish, 10 of which have been tagged. If a fisherman’s catch consists of 7 fish, selected at random and without replacement. Give an example of a random variable that can be defined if we are interested in knowing the number of tagged fish that are caught? What is the probability that exactly 2 tagged fish are caught? Define the random variable, its purpose, and the formula/concept that you would use. Applied to Quality Control Q20. My manufacturing firm makes 100 cars every day out of which 10 are defective; the quality control inspector tests drives 5 different cars. Based on the sample, the quality control inspector will make a generalization about the whole batch of 100 cars that I have on that day. Let d denote the number of defective cars in the sample What are the values that d can take (given the information provided above)? What is the probability that the quality control inspector will conclude that: (a) 0% of the cars are defective- call this P(d=0); (b) 20% of the cars are defective- call this P(d=1); (c) 40% of the cars are defective- call this P(d=2); (d) 60% of the cars are defective- call this P(d=3),(e) 80% of the cars are defective- call this P(d=4), and (f) 100% of the cars are defective- call this P(d=5) What is P(d=0)+ P(d=1)+ P(d=2)+ P(d=3)+ P(d=4)+ P(d=5) Let’s assume that the quality control inspector has been doing the testing for a while (say for the past 1000 days). What is the average # of defective cars that he found? Q21. Assume that the quality control inspector is selecting 1 car at a time and the car that he tested is put back in the pool of possible cars that he can test (sample with replacement). Let d denote the number of defective cars in the sample (n) What are the values that d can take (given the information provided above)? What is the probability that the quality control inspector will conclude that: (a) 0% of the cars are defective, (b) 20% of the cars are defective, (c) 40% of the cars are defective, (d) 60% of the cars are defective, (e) 80% of the cars are defective, and (f) 100% of the cars are defective. Let’s call these P(d=0)….P(d=5) What is P(d=0)+ P(d=1)+ P(d=2)+ P(d=3)+ P(d=4)+ P(d=5) Let’s assume that the quality control inspector has been doing the testing for a while (say for the past 1000 days). What is the average # of defective cars that he found? Interesting Problems Q22. A closet contains n pairs of shoes. If 2r shoes are chosen at random (2r<n), what is the probability that there will be no matching pair in the sample? Q23. In a draft lottery containing the 366 days of the leap year, what is the probability that the first 180 days drawn (without replacement) are evenly distributed among the 12 months? What is the probability that the first 30 days drawn contain none from September? Q25. You and I play a coin-tossing game. If the coin falls heads I score one, if tails, you score one. In the beginning, the score is zero. What is the probability that after 2n throws our scores are equal? What is the probability that after 2n+1 throws my score is three more than yours?

Assignment 2 Conditional Probability, Bayes Theorem, and Random Variables Conditional Probability and Bayes’ Theorem Problems 1-14 from Problem Set on Conditional Probability and Bayes’ Theorem I am including all the question here so that there is no confusion. Q1. Pair of six sided dices are rolled and the outcome is noted: What is the sample space? What is the size of the sample space? Suppose all we are interested in is the sum of the two outcomes. What is the probability that the sum of the two is 6? 7? 8? (Note: This can be solved using both enumeration and conditional probability method). Here, it makes more sense to use the enumeration approach than conditional probability. It is, however, listed here to set the stage for Q5. What is the probability that the sum of the two is above 5 and the two numbers are equal? Express this question in terms of events A, B, and set operators. What is the probability that the sum of the two is above 5 or the two numbers are equal? Express this question in terms of events A, B, and set operators. Q2. If P(A)=0.4, P(B)=0.5 and P(A∩B)=0.3 What is the value of (a) P(A|B) and (b) P(B|A) Q3. At a fair, a vendor has 25 helium balloons on strings: 10 balloons are yellow, 8 are red, and 7 are green. A balloon is selected at random and sold. Given that the balloon sold is yellow, what is the probability that the next balloon selected at random is also yellow? Q4. A bowl contains seven blue chips and three red chips. Two chips are to be drawn at random and without replacement. What is the probability that the fist chip is a red chip and the second a blue? Express this question in terms of events A, B, and set operators and use conditional probability. Q5. Three six sided dices are rolled and the outcome is noted: What is the size of the sample space? What is the probability that the sum of the three numbers is 6? 13? 18? Solve using conditional probability How does the concept of conditional probability help? Q6. A grade school boy has 5 blue and four white marbles in his left pocket and four blue and five white marbles in his right pocket. If he transfers one marble at random from his left pocket to his right pocket, what is the probability of his then drawing a blue marble from his right pocket? Q7. In a certain factory, machine I, II, and III are all producing springs of the same length. Of their production, machines I, II, and III produce 2%, 1%, and 3% defective springs respectively. Of the total production of springs in the factory, machine I produces 35%, machine II produces 25%, and machine III produces 40%. If one spring is selected at random from the total springs produced in a day, what is the probability that it is defective? Given that the selected spring is defective, what is the probability that it was produced on machine III? Q8. Bowl B1 contains 2 white chips, bowl B2 contains 2 red chips, bowl B3 contains 2 white and 2 red chips, and Bowl B4 contains 3 white chips and 1 red chip. The probabilities of selecting bowl B1, B2, B3, and B4 are 1/2, 1/4, 1/8, and 1/8 respectively. A bowl is selected using these probabilities, and a chip is then drawn at random. Find P(W), the probability of drawing a white chip P(B1|W): the probability that bowl B1 was selected, given that a white chip was drawn. Q9. A pap smear is a screening procedure used to detect cervical cancer. For women with this cancer, there are about 16% false negative. For women without cervical cancer, there are about 19% false positive. In the US, there are about 8 women in 100,000 who have this cancer. What is the probability that a woman who has been tested positive actually has cervical cancer? Q10. There is a new diagnostic test for a disease that occurs in about 0.05% of the population. The test is not perfect but will detect a person with the disease 99% of the time. It will, however, say that a person without the disease has the disease about 3% of the time. A person is selected at random from the population and the test indicates that this person has the disease. What are the conditional probabilities that The person has the disease The person does not have the disease Q11. Consider two urns: the first contains two white and seven black balls, and the second contains five white and six black balls. We flip a fair coin and then draw a ball from the first urn or the second urn depending on whether the outcome was a head or a tails. What is the conditional probability that the outcome of the toss was heads given that a white ball was selected? Q12. In answering a question on a multiple-choice test a student either knows the answer or guesses. Let p be the probability that she knows the answer. Assume that a student who guesses at the answer will be correct with probability 1/m where m is the number of multiple choice alternatives. What is the conditional probability that a student knew the answer given that she answered it correctly? Q13. A laboratory blood test is 95% effective in detecting a certain disease when it is, in fact, present. However, the test also yields a “false positive” result for 1% of the healthy persons tested (i.e., if a healthy person is tested, then, with probability 0.01, the test result will imply that he has the disease.). If 0.5% of the population actually have the disease, what is the probability a person has the disease given that his test results are positive? Q14. An urn contains b black balls and r red balls. One of the balls is drawn at random, but when it is put back in the urn, c additional balls of the same color are put in it with it. Now suppose that we draw another ball. What is the probability that the first ball drawn was black given that the second ball drawn was red? Random Variables Q15. Suppose an experiment consists of tossing two six sided fair dice and observing the outcomes. What is the sample space? Let Y denote the sum of the two numbers that appear on the dice. Define Y to be a random variable. What are the values that the random variable Y can take? What does it mean if we say Y=7? What does it mean if I say that Y<7? Q16. Suppose an experiment consists of picking a sample of size n from a population of size N. Assume that n≪N. Also, assume that the population contains D defective parts and N-D non defective parts, where n

salt water contains n sodium ions (Na+) per cubic meter and n chloride ions (cI-) per cubic meter. A battery is connected to metal. A battery is connected to metal rods that dip into a narrow pipe full of the salt water. the cross sectional area of the pipe is A what is the direction of conventional current flow in the salt water? 1. to the right, 2. to the left, 3. there is no conventional current because the motion of the positive and negative ions cancel each other out.

salt water contains n sodium ions (Na+) per cubic meter and n chloride ions (cI-) per cubic meter. A battery is connected to metal. A battery is connected to metal rods that dip into a narrow pipe full of the salt water. the cross sectional area of the pipe is A what is the direction of conventional current flow in the salt water? 1. to the right, 2. to the left, 3. there is no conventional current because the motion of the positive and negative ions cancel each other out.

answer 2
Assignment 4 Due: 11:59pm on Wednesday, February 26, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy ± Two Forces Acting at a Point Two forces, and , act at a point. has a magnitude of 9.80 and is directed at an angle of 56.0 above the negative x axis in the second quadrant. has a magnitude of 5.20 and is directed at an angle of 54.1 below the negative x axis in the third quadrant. Part A What is the x component of the resultant force? Express your answer in newtons. Hint 1. How to approach the problem The resultant force is defined as the vector sum of all forces. Thus, its x component is the sum of the x components of the forces, and its y component is the sum of the y components of the forces. Hint 2. Find the x component of Find the x component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . F 1 F  2 F  1 N  F  2 N  F 1 F  1 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 Hint 2. Find the direction of is directed at an angle of 56.0 above the x axis in the second quadrant. When you calculate the components of , however, the direction of the force is commonly expressed in terms of the angle that the vector representing the force forms with the positive x axis. What is the angle that forms with the positive x axis? Select an answer from the following list, where 56.0 . ANSWER: ANSWER: Hint 3. Find the x component of Find the x component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , F 1 F 1  F  1 F  1  =   180 −  180 +  90 +  -5.48 N F 2 F  2 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Typesetting math: 100% and if . Hint 2. Find the direction of is directed at an angle of 54.1 below the x axis in the third quadrant. When you calculate the components of , however, the direction of the force is commonly expressed in terms of the angle that the vector representing the force forms with the positive x axis. What is the angle that forms with the positive x axis? Select an answer from the following list, where 54.1 . ANSWER: ANSWER: ANSWER: Correct Part B What is the y component of the resultant force? Express your answer in newtons. Ax < 0 Ay <  <  < 3 2 F 2 F 2  F 2 F  2  =   180 −   − 180 −90 −  -3.05 N -8.53 N Typesetting math: 100% Hint 1. How to approach the problem Follow the same procedure that you used in Part A to find the x component of the resultant force, though now calculate the y components of the two forces. Hint 2. Find the y component of Find the y component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . ANSWER: Hint 3. Find the y component of Find the y component of . Express your answer in newtons. Hint 1. Components of a vector F 1 F  1 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 8.12 N F 2 F  2 Typesetting math: 100% Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . ANSWER: ANSWER: Correct Part C What is the magnitude of the resultant force? Express your answer in newtons. Hint 1. Magnitude of a vector Consider a vector , whose components are and . The magnitude of is . A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 -4.21 N 3.91 N A Ax Ay A A = A + 2 x A2 y −−−−−−−  Typesetting math: 100% ANSWER: Correct Enhanced EOC: Problem 5.9 The figure shows acceleration-versus-force graphs for two objects pulled by rubber bands. You may want to review ( pages 127 - 130) . For help with math skills, you may want to review: Finding the Slope of a Line from a Graph Part A What is the mass ratio ? Express your answer using two significant figures. 9.38 N m1 m2 Typesetting math: 100% Hint 1. How to approach the problem How are the acceleration and the force on an object related to its mass? How is the slope of each line in the figure related to each object's mass? For each line, what two points are easy to measure accurately to determine the slope of line? How is the slope determined from the x and y coordinates of the two points you chose for each line? ANSWER: Correct A World-Class Sprinter World-class sprinters can accelerate out of the starting blocks with an acceleration that is nearly horizontal and has magnitude . Part A How much horizontal force must a sprinter of mass 54 exert on the starting blocks to produce this acceleration? Express your answer in newtons using two significant figures. Hint 1. Newton's 2nd law of motion According to Newton's 2nd law of motion, if a net external force acts on a body, the body accelerates, and the net force is equal to the mass of the body times the acceleration of the body: . ANSWER: = 0.36 m1 m2 15 m/s2 F kg Fnet m a Fnet = ma F = 810 N Typesetting math: 100% Correct Part B Which body exerts the force that propels the sprinter, the blocks or the sprinter? Hint 1. How to approach the question To start moving forward, sprinters push backward on the starting blocks with their feet. Newton's 3rd law tells you that the blocks exert a force on the sprinter of the same magnitude, but opposite in direction. ANSWER: Correct To start moving forward, sprinters push backward on the starting blocks with their feet. As a reaction, the blocks push forward on their feet with a force of the same magnitude. This external force accelerates the sprinter forward. Problem 5.12 The figure shows an acceleration-versus-force graph for a 600 object. the blocks the sprinter g Typesetting math: 100% Part A What must equal in order for the graph to be correct? Express your answer with the appropriate units. ANSWER: Correct Part B What must equal in order for the graph to be correct? Express your answer with the appropriate units. ANSWER: Correct Free-Body Diagrams Learning Goal: To gain practice drawing free-body diagrams Whenever you face a problem involving forces, always start with a free-body diagram. a1 a1 = 1.67 m s2 a2 a2 = 3.33 m s2 Typesetting math: 100% To draw a free-body diagram use the following steps: Isolate the object of interest. It is customary to represent the object of interest as a point 1. in your diagram. Identify all the forces acting on the object and their directions. Do not include forces acting on other objects in the problem. Also, do not include quantities, such as velocities and accelerations, that are not forces. 2. Draw the vectors for each force acting on your object of interest. When possible, the length of the force vectors you draw should represent the relative magnitudes of the forces acting on the object. 3. In most problems, after you have drawn the free-body diagrams, you will explicitly label your coordinate axes and directions. Always make the object of interest the origin of your coordinate system. Then you will need to divide the forces into x and y components, sum the x and y forces, and apply Newton's first or second law. In this problem you will only draw the free-body diagram. Suppose that you are asked to solve the following problem: Chadwick is pushing a piano across a level floor (see the figure). The piano can slide across the floor without friction. If Chadwick applies a horizontal force to the piano, what is the piano's acceleration? To solve this problem you should start by drawing a free-body diagram. Part A Determine the object of interest for the situation described in the problem introduction. Hint 1. How to approach the problem You should first think about the question you are trying to answer: What is the acceleration of the piano? The object of interest in this situation will be the object whose acceleration you are asked to find. ANSWER: Typesetting math: 100% Correct Part B Identify the forces acting on the object of interest. From the list below, select the forces that act on the piano. Check all that apply. ANSWER: Correct Now that you have identified the forces acting on the piano, you should draw the free-body diagram. Draw the length of your vectors to represent the relative magnitudes of the forces, but you don't need to worry about the exact scale. You won't have the exact value of all of the forces until you finish solving the problem. To maximize your learning, you should draw the diagram yourself before looking at the choices in the next part. You are on your honor to do so. Part C For this situation you should draw a free-body diagram for the floor. Chadwick. the piano. acceleration of the piano gravitational force acting on the piano (piano's weight) speed of the piano gravitational force acting on Chadwick (Chadwick's weight) force of the floor on the piano (normal force) force of the piano on the floor force of Chadwick on the piano force of the piano pushing on Chadwick Typesetting math: 100% Select the choice that best matches the free-body diagram you have drawn for the piano. Hint 1. Determine the directions and relative magnitudes of the forces Which of the following statements best describes the correct directions and relative magnitudes of the forces involved? ANSWER: ANSWER: The normal force and weight are both upward and the pushing force is horizontal. The normal force and weight are both downward and the pushing force is horizontal. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force has a greater magnitude than the weight. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force and weight have the same magnitude. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force has a smaller magnitude than the weight. Typesetting math: 100% Typesetting math: 100% Correct If you were actually going to solve this problem rather than just draw the free-body diagram, you would need to define the coordinate system. Choose the position of the piano as the origin. In this case it is simplest to let the y axis point vertically upward and the x axis point horizontally to the right, in the direction of the acceleration. Chadwick now needs to push the piano up a ramp and into a moving van. at left. The ramp is frictionless. Is Chadwick strong enough to push the piano up the ramp alone or must he get help? To solve this problem you should start by drawing a free-body diagram. Part D Determine the object of interest for this situation. ANSWER: Correct Now draw the free-body diagram of the piano in this new situation. Follow the same sequence of steps that you followed for the first situation. Again draw your diagram before you look at the choices For this situation, you should draw a free-body diagram for the ramp. Chadwick. the piano. Typesetting math: 100% below. Part E Which diagram accurately represents the free-body diagram for the piano? ANSWER: Typesetting math: 100% Typesetting math: 100% Correct In working problems like this one that involve an incline, it is most often easiest to select a coordinate system that is not vertical and horizontal. Instead, choose the x axis so that it is parallel to the incline and choose the y axis so that it is perpendicular to the incline. Problem 5.18 The figure shows two of the three forces acting on an object in equilibrium. Part A Redraw the diagram, showing all three forces. Label the third force . Draw the force vector starting at the black dot. The location and orientation of the vector will be graded. The length of the vector will not be graded. ANSWER: F  3 Typesetting math: 100% Correct Problem 5.25 An ice hockey puck glides across frictionless ice. Part A Identify all forces acting on the object. ANSWER: Typesetting math: 100% Correct Part B Draw a free-body diagram of the ice hockey puck. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Normal force ; Gravity Normal force ; Gravity ; Kinetic friction Tension ; Weight Thrust ; Gravity n F  G n F  G fk  T  w Fthrust  F  G Typesetting math: 100% Correct Problem 5.26 Your physics textbook is sliding to the right across the table. Part A Identify all forces acting on the object. ANSWER: Typesetting math: 100% Correct Part B Draw a free-body diagram of the object. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Weight ; Kinetic friction Thrust ; Kinetic friction Normal force ; Weight ; Kinetic friction Normal force ; Weight ; Static friction w fk  Fthrust  fk  n w fk  n w fs  Typesetting math: 100% Correct Enhanced EOC: Problem 5.35 A constant force is applied to an object, causing the object to accelerate at 13 . You may want to review ( pages 127 - 130) . For help with math skills, you may want to review: Proportions I Proportions II Part A m/s2 Typesetting math: 100% What will the acceleration be if the force is halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the force is halved but the mass remains the same? ANSWER: Correct Part B What will the acceleration be if the object's mass is halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the mass is halved but the force remains the same? ANSWER: Correct Part C a = 6.50 m s2 a = 26.0 m s2 Typesetting math: 100% What will the acceleration be if the force and the object's mass are both halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if both the force and mass are reduced by a factor of two? ANSWER: Correct Part D What will the acceleration be if the force is halved and the object's mass is doubled? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the force is decreased by a factor of two and the mass is increased by a factor of two? Check your answer by choosing numerical values of the force and mass, and then halve the force and double the mass. ANSWER: Correct a = 13.0 m s2 a = 3.25 m s2 Typesetting math: 100% Problem 5.44 A rocket is being launched straight up. Air resistance is not negligible. Part A Which of the following is the correct motion diagram for the situation described above? Enter the letter that corresponds with the best answer. ANSWER: Correct Part B Draw a free-body diagram. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Typesetting math: 100% Correct Score Summary: Your score on this assignment is 99.7%. You received 63.82 out of a possible total of 64 points. Typesetting math: 100%

Assignment 4 Due: 11:59pm on Wednesday, February 26, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy ± Two Forces Acting at a Point Two forces, and , act at a point. has a magnitude of 9.80 and is directed at an angle of 56.0 above the negative x axis in the second quadrant. has a magnitude of 5.20 and is directed at an angle of 54.1 below the negative x axis in the third quadrant. Part A What is the x component of the resultant force? Express your answer in newtons. Hint 1. How to approach the problem The resultant force is defined as the vector sum of all forces. Thus, its x component is the sum of the x components of the forces, and its y component is the sum of the y components of the forces. Hint 2. Find the x component of Find the x component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . F 1 F  2 F  1 N  F  2 N  F 1 F  1 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 Hint 2. Find the direction of is directed at an angle of 56.0 above the x axis in the second quadrant. When you calculate the components of , however, the direction of the force is commonly expressed in terms of the angle that the vector representing the force forms with the positive x axis. What is the angle that forms with the positive x axis? Select an answer from the following list, where 56.0 . ANSWER: ANSWER: Hint 3. Find the x component of Find the x component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , F 1 F 1  F  1 F  1  =   180 −  180 +  90 +  -5.48 N F 2 F  2 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Typesetting math: 100% and if . Hint 2. Find the direction of is directed at an angle of 54.1 below the x axis in the third quadrant. When you calculate the components of , however, the direction of the force is commonly expressed in terms of the angle that the vector representing the force forms with the positive x axis. What is the angle that forms with the positive x axis? Select an answer from the following list, where 54.1 . ANSWER: ANSWER: ANSWER: Correct Part B What is the y component of the resultant force? Express your answer in newtons. Ax < 0 Ay <  <  < 3 2 F 2 F 2  F 2 F  2  =   180 −   − 180 −90 −  -3.05 N -8.53 N Typesetting math: 100% Hint 1. How to approach the problem Follow the same procedure that you used in Part A to find the x component of the resultant force, though now calculate the y components of the two forces. Hint 2. Find the y component of Find the y component of . Express your answer in newtons. Hint 1. Components of a vector Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . ANSWER: Hint 3. Find the y component of Find the y component of . Express your answer in newtons. Hint 1. Components of a vector F 1 F  1 A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 8.12 N F 2 F  2 Typesetting math: 100% Consider a vector that forms an angle with the positive x axis. The x and y components of are, respectively, and , where is the magnitude of the vector. Note that and if , and if . ANSWER: ANSWER: Correct Part C What is the magnitude of the resultant force? Express your answer in newtons. Hint 1. Magnitude of a vector Consider a vector , whose components are and . The magnitude of is . A  A Ax = Acos  Ay = Asin  A Ax < 0 Ay > 0  <  <  2 Ax < 0 Ay < 0  <  < 3 2 -4.21 N 3.91 N A Ax Ay A A = A + 2 x A2 y −−−−−−−  Typesetting math: 100% ANSWER: Correct Enhanced EOC: Problem 5.9 The figure shows acceleration-versus-force graphs for two objects pulled by rubber bands. You may want to review ( pages 127 - 130) . For help with math skills, you may want to review: Finding the Slope of a Line from a Graph Part A What is the mass ratio ? Express your answer using two significant figures. 9.38 N m1 m2 Typesetting math: 100% Hint 1. How to approach the problem How are the acceleration and the force on an object related to its mass? How is the slope of each line in the figure related to each object's mass? For each line, what two points are easy to measure accurately to determine the slope of line? How is the slope determined from the x and y coordinates of the two points you chose for each line? ANSWER: Correct A World-Class Sprinter World-class sprinters can accelerate out of the starting blocks with an acceleration that is nearly horizontal and has magnitude . Part A How much horizontal force must a sprinter of mass 54 exert on the starting blocks to produce this acceleration? Express your answer in newtons using two significant figures. Hint 1. Newton's 2nd law of motion According to Newton's 2nd law of motion, if a net external force acts on a body, the body accelerates, and the net force is equal to the mass of the body times the acceleration of the body: . ANSWER: = 0.36 m1 m2 15 m/s2 F kg Fnet m a Fnet = ma F = 810 N Typesetting math: 100% Correct Part B Which body exerts the force that propels the sprinter, the blocks or the sprinter? Hint 1. How to approach the question To start moving forward, sprinters push backward on the starting blocks with their feet. Newton's 3rd law tells you that the blocks exert a force on the sprinter of the same magnitude, but opposite in direction. ANSWER: Correct To start moving forward, sprinters push backward on the starting blocks with their feet. As a reaction, the blocks push forward on their feet with a force of the same magnitude. This external force accelerates the sprinter forward. Problem 5.12 The figure shows an acceleration-versus-force graph for a 600 object. the blocks the sprinter g Typesetting math: 100% Part A What must equal in order for the graph to be correct? Express your answer with the appropriate units. ANSWER: Correct Part B What must equal in order for the graph to be correct? Express your answer with the appropriate units. ANSWER: Correct Free-Body Diagrams Learning Goal: To gain practice drawing free-body diagrams Whenever you face a problem involving forces, always start with a free-body diagram. a1 a1 = 1.67 m s2 a2 a2 = 3.33 m s2 Typesetting math: 100% To draw a free-body diagram use the following steps: Isolate the object of interest. It is customary to represent the object of interest as a point 1. in your diagram. Identify all the forces acting on the object and their directions. Do not include forces acting on other objects in the problem. Also, do not include quantities, such as velocities and accelerations, that are not forces. 2. Draw the vectors for each force acting on your object of interest. When possible, the length of the force vectors you draw should represent the relative magnitudes of the forces acting on the object. 3. In most problems, after you have drawn the free-body diagrams, you will explicitly label your coordinate axes and directions. Always make the object of interest the origin of your coordinate system. Then you will need to divide the forces into x and y components, sum the x and y forces, and apply Newton's first or second law. In this problem you will only draw the free-body diagram. Suppose that you are asked to solve the following problem: Chadwick is pushing a piano across a level floor (see the figure). The piano can slide across the floor without friction. If Chadwick applies a horizontal force to the piano, what is the piano's acceleration? To solve this problem you should start by drawing a free-body diagram. Part A Determine the object of interest for the situation described in the problem introduction. Hint 1. How to approach the problem You should first think about the question you are trying to answer: What is the acceleration of the piano? The object of interest in this situation will be the object whose acceleration you are asked to find. ANSWER: Typesetting math: 100% Correct Part B Identify the forces acting on the object of interest. From the list below, select the forces that act on the piano. Check all that apply. ANSWER: Correct Now that you have identified the forces acting on the piano, you should draw the free-body diagram. Draw the length of your vectors to represent the relative magnitudes of the forces, but you don't need to worry about the exact scale. You won't have the exact value of all of the forces until you finish solving the problem. To maximize your learning, you should draw the diagram yourself before looking at the choices in the next part. You are on your honor to do so. Part C For this situation you should draw a free-body diagram for the floor. Chadwick. the piano. acceleration of the piano gravitational force acting on the piano (piano's weight) speed of the piano gravitational force acting on Chadwick (Chadwick's weight) force of the floor on the piano (normal force) force of the piano on the floor force of Chadwick on the piano force of the piano pushing on Chadwick Typesetting math: 100% Select the choice that best matches the free-body diagram you have drawn for the piano. Hint 1. Determine the directions and relative magnitudes of the forces Which of the following statements best describes the correct directions and relative magnitudes of the forces involved? ANSWER: ANSWER: The normal force and weight are both upward and the pushing force is horizontal. The normal force and weight are both downward and the pushing force is horizontal. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force has a greater magnitude than the weight. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force and weight have the same magnitude. The normal force is upward, the weight is downward, and the pushing force is horizontal. The normal force has a smaller magnitude than the weight. Typesetting math: 100% Typesetting math: 100% Correct If you were actually going to solve this problem rather than just draw the free-body diagram, you would need to define the coordinate system. Choose the position of the piano as the origin. In this case it is simplest to let the y axis point vertically upward and the x axis point horizontally to the right, in the direction of the acceleration. Chadwick now needs to push the piano up a ramp and into a moving van. at left. The ramp is frictionless. Is Chadwick strong enough to push the piano up the ramp alone or must he get help? To solve this problem you should start by drawing a free-body diagram. Part D Determine the object of interest for this situation. ANSWER: Correct Now draw the free-body diagram of the piano in this new situation. Follow the same sequence of steps that you followed for the first situation. Again draw your diagram before you look at the choices For this situation, you should draw a free-body diagram for the ramp. Chadwick. the piano. Typesetting math: 100% below. Part E Which diagram accurately represents the free-body diagram for the piano? ANSWER: Typesetting math: 100% Typesetting math: 100% Correct In working problems like this one that involve an incline, it is most often easiest to select a coordinate system that is not vertical and horizontal. Instead, choose the x axis so that it is parallel to the incline and choose the y axis so that it is perpendicular to the incline. Problem 5.18 The figure shows two of the three forces acting on an object in equilibrium. Part A Redraw the diagram, showing all three forces. Label the third force . Draw the force vector starting at the black dot. The location and orientation of the vector will be graded. The length of the vector will not be graded. ANSWER: F  3 Typesetting math: 100% Correct Problem 5.25 An ice hockey puck glides across frictionless ice. Part A Identify all forces acting on the object. ANSWER: Typesetting math: 100% Correct Part B Draw a free-body diagram of the ice hockey puck. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Normal force ; Gravity Normal force ; Gravity ; Kinetic friction Tension ; Weight Thrust ; Gravity n F  G n F  G fk  T  w Fthrust  F  G Typesetting math: 100% Correct Problem 5.26 Your physics textbook is sliding to the right across the table. Part A Identify all forces acting on the object. ANSWER: Typesetting math: 100% Correct Part B Draw a free-body diagram of the object. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Weight ; Kinetic friction Thrust ; Kinetic friction Normal force ; Weight ; Kinetic friction Normal force ; Weight ; Static friction w fk  Fthrust  fk  n w fk  n w fs  Typesetting math: 100% Correct Enhanced EOC: Problem 5.35 A constant force is applied to an object, causing the object to accelerate at 13 . You may want to review ( pages 127 - 130) . For help with math skills, you may want to review: Proportions I Proportions II Part A m/s2 Typesetting math: 100% What will the acceleration be if the force is halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the force is halved but the mass remains the same? ANSWER: Correct Part B What will the acceleration be if the object's mass is halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the mass is halved but the force remains the same? ANSWER: Correct Part C a = 6.50 m s2 a = 26.0 m s2 Typesetting math: 100% What will the acceleration be if the force and the object's mass are both halved? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if both the force and mass are reduced by a factor of two? ANSWER: Correct Part D What will the acceleration be if the force is halved and the object's mass is doubled? Express your answer with the appropriate units. Hint 1. How to approach the problem How is the acceleration of an object related to its mass and the force applied? Expressing the acceleration in terms of the force and mass, what happens to the acceleration if the force is decreased by a factor of two and the mass is increased by a factor of two? Check your answer by choosing numerical values of the force and mass, and then halve the force and double the mass. ANSWER: Correct a = 13.0 m s2 a = 3.25 m s2 Typesetting math: 100% Problem 5.44 A rocket is being launched straight up. Air resistance is not negligible. Part A Which of the following is the correct motion diagram for the situation described above? Enter the letter that corresponds with the best answer. ANSWER: Correct Part B Draw a free-body diagram. Draw the force vectors with their tails at the dot. The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded. ANSWER: Typesetting math: 100% Correct Score Summary: Your score on this assignment is 99.7%. You received 63.82 out of a possible total of 64 points. Typesetting math: 100%

please email info@checkyourstudy.com
Chapter 06 Reading Questions Due: 11:59pm on Friday, May 23, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Chapter 6 Reading Quiz Question 17 Part A Which of the following represents an example of intraspecific exploitation competition? ANSWER: Chapter 6 Reading Quiz Question 3 Part A A species’s realized niche _____. ANSWER: Chapter 6 Reading Quiz Question 2 Part A Two species of ant compete for limited resources in a front yard, until only one species is able to remain. This is an example of _____. ANSWER: Hungry and fighting for a meal, a jackal quickly consumes the carcass of a young antelope while fighting off the feeding efforts of a vulture. Two species of worker ants converge on pieces of a donut left behind from the people in the park. The leaves of the huge hickory tree overshadow the young hickory tree saplings struggling for light just below. Spotting a fresh source of grasses, the large male bison moves over to graze, pushing the smaller bison out of the way. is smaller than the fundamental niche because of the constraints of competition is broader than a species’s fundamental niche does not overlap with similar species includes environmental conditions that are not included in the fundamental niche Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 20 Part A In which of the following situations would we expect a parasite to spread the fastest? ANSWER: Chapter 6 Reading Quiz Question 6 Part A Many plants have evolved adaptations to discourage herbivore feeding. Which one of the following is an example of such coevolution between bison and prairie plants? ANSWER: Chapter 6 Reading Quiz Question 5 Part A When predators selectively prey on the old and sick members of a prey population, they _____. ANSWER: mutualism intraspecific competition the competitive exclusion principle niche differentiation concentrated hosts with slowly moving vectors widely dispersed hosts with rapidly moving vectors concentrated hosts with rapidly moving vectors widely dispersed hosts with slow-moving vectors the ability to regrow after a wildfire thorns the production of nutritious fruits longer and thicker roots Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 21 Part A Cattle egrets are large white birds that follow grazing cattle. The cattle disturb the grass and stir up insects upon which the egrets feed. The cattle do not seem to mind the birds and gain nothing from this relationship. This relationship between cattle and cattle egrets is a type of _____. ANSWER: Chapter 6 Reading Quiz Question 8 Part A Which of the following is a mutualistic relationship that has a significant effect on an entire ecological community? ANSWER: Chapter 6 Reading Quiz Question 7 Part A Which one of the following relationships would be considered a win/win? ANSWER: cause the overall health of the prey population to increase illustrate the process of prey switching increase the likelihood of parasitic infections of the prey cause the overall health of the prey population to decrease parasitism commensalism mimicry mutualism Polar bears are the top predator influencing the abundance of seals and sea lions in a region. Hermit crabs inhabit the abandoned shells of marine snails that died long ago. Fungus-plant root associations benefit most of the plants living in a prairie. Mosquitoes function as a vector in the widespread transmission of malaria to people living in Ecuador. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 23 Part A In examining a terrestrial food web, we expect that the _____. ANSWER: Chapter 6 Reading Quiz Question 22 Part A Energy is lost as it moves from one trophic level to the next because _____. ANSWER: Chapter 6 Reading Quiz Question 11 Part A The research on the reintroduction of wolves into Yellowstone National Park reveals that in this ecosystem, wolves represent _____. ANSWER: mutualism predation parasitism commensalism biomass of primary consumers exceeds the biomass of producers number of secondary consumers exceeds the number of producers biomass of primary consumers exceeds the biomass of secondary consumers number of tertiary consumers exceeds the number of secondary consumers one trophic level does not consume the entire trophic level below it some of the calories consumed drive cellular activities and do not add mass some ingested materials are undigested and eliminated All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 10 Part A Overhunting of deer followed by a very difficult winter caused the deer population on an island to drop by 80%. In the next two years, visitors to the island were surprised to see many young trees sprouting up at the edges of the forest. This change in the number of saplings as a result of the decline of the deer population represents _____. ANSWER: Chapter 6 Reading Quiz Question 24 Part A The May 18, 1980, eruption of Mount Saint Helens blasted away soil and produced massive mudflows that scoured the adjacent region down to bare rock. Pumice rock that covered the area is eroding down to smaller gravel. This situation represents _____. ANSWER: Chapter 6 Reading Quiz Question 15 Part A In some ecosystems, succession increases the chance of disturbance. In these ecosystems, _____. a keystone producer a keystone herbivore a vital primary consumer a keystone predator a trophic cascade a decline in trophic level efficiency the emergence of a new ecological community a loss of a trophic level from a food web primary succession with the removal of all ecological legacies secondary succession with the removal of all ecological legacies secondary succession with several ecological legacies primary succession with several ecological legacies Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 7 5/21/2014 8:01 PM ANSWER: Chapter 6 Reading Quiz Question 12 Part A A forest is logged, leaving behind the seeds and saplings of many shrubs and trees. These seeds and saplings represent _____. ANSWER: Chapter 6 Reading Quiz Question 13 Part A During primary succession, populations of different species replace one another over time because of _____. ANSWER: Chapter 6 Reading Quiz Question 14 Part A Which one of the following represents a climax community in southern Alaska? ANSWER: ecosystems begin again with primary succession climax communities are expected climax communities may not occur disturbances usually result in virtually no ecological legacy ecological legacies a climax community primary succession pioneer species migration facilitation competition All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 9 Part A In general, _____. ANSWER: Score Summary: Your score on this assignment is 0.0%. You received 0 out of a possible total of 19 points. the group of species associated with a white spruce forest lichens and mosses that colonize exposed rock birch and alder trees herbs and a few low shrubs that replace lichens and mosses food webs usually have 8-10 trophic levels food webs are interconnected food chains food chains consist of many interrelated food webs food webs consist of either consumers or producers Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 7 5/21/2014 8:01 PM

Chapter 06 Reading Questions Due: 11:59pm on Friday, May 23, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Chapter 6 Reading Quiz Question 17 Part A Which of the following represents an example of intraspecific exploitation competition? ANSWER: Chapter 6 Reading Quiz Question 3 Part A A species’s realized niche _____. ANSWER: Chapter 6 Reading Quiz Question 2 Part A Two species of ant compete for limited resources in a front yard, until only one species is able to remain. This is an example of _____. ANSWER: Hungry and fighting for a meal, a jackal quickly consumes the carcass of a young antelope while fighting off the feeding efforts of a vulture. Two species of worker ants converge on pieces of a donut left behind from the people in the park. The leaves of the huge hickory tree overshadow the young hickory tree saplings struggling for light just below. Spotting a fresh source of grasses, the large male bison moves over to graze, pushing the smaller bison out of the way. is smaller than the fundamental niche because of the constraints of competition is broader than a species’s fundamental niche does not overlap with similar species includes environmental conditions that are not included in the fundamental niche Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 20 Part A In which of the following situations would we expect a parasite to spread the fastest? ANSWER: Chapter 6 Reading Quiz Question 6 Part A Many plants have evolved adaptations to discourage herbivore feeding. Which one of the following is an example of such coevolution between bison and prairie plants? ANSWER: Chapter 6 Reading Quiz Question 5 Part A When predators selectively prey on the old and sick members of a prey population, they _____. ANSWER: mutualism intraspecific competition the competitive exclusion principle niche differentiation concentrated hosts with slowly moving vectors widely dispersed hosts with rapidly moving vectors concentrated hosts with rapidly moving vectors widely dispersed hosts with slow-moving vectors the ability to regrow after a wildfire thorns the production of nutritious fruits longer and thicker roots Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 21 Part A Cattle egrets are large white birds that follow grazing cattle. The cattle disturb the grass and stir up insects upon which the egrets feed. The cattle do not seem to mind the birds and gain nothing from this relationship. This relationship between cattle and cattle egrets is a type of _____. ANSWER: Chapter 6 Reading Quiz Question 8 Part A Which of the following is a mutualistic relationship that has a significant effect on an entire ecological community? ANSWER: Chapter 6 Reading Quiz Question 7 Part A Which one of the following relationships would be considered a win/win? ANSWER: cause the overall health of the prey population to increase illustrate the process of prey switching increase the likelihood of parasitic infections of the prey cause the overall health of the prey population to decrease parasitism commensalism mimicry mutualism Polar bears are the top predator influencing the abundance of seals and sea lions in a region. Hermit crabs inhabit the abandoned shells of marine snails that died long ago. Fungus-plant root associations benefit most of the plants living in a prairie. Mosquitoes function as a vector in the widespread transmission of malaria to people living in Ecuador. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 23 Part A In examining a terrestrial food web, we expect that the _____. ANSWER: Chapter 6 Reading Quiz Question 22 Part A Energy is lost as it moves from one trophic level to the next because _____. ANSWER: Chapter 6 Reading Quiz Question 11 Part A The research on the reintroduction of wolves into Yellowstone National Park reveals that in this ecosystem, wolves represent _____. ANSWER: mutualism predation parasitism commensalism biomass of primary consumers exceeds the biomass of producers number of secondary consumers exceeds the number of producers biomass of primary consumers exceeds the biomass of secondary consumers number of tertiary consumers exceeds the number of secondary consumers one trophic level does not consume the entire trophic level below it some of the calories consumed drive cellular activities and do not add mass some ingested materials are undigested and eliminated All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 10 Part A Overhunting of deer followed by a very difficult winter caused the deer population on an island to drop by 80%. In the next two years, visitors to the island were surprised to see many young trees sprouting up at the edges of the forest. This change in the number of saplings as a result of the decline of the deer population represents _____. ANSWER: Chapter 6 Reading Quiz Question 24 Part A The May 18, 1980, eruption of Mount Saint Helens blasted away soil and produced massive mudflows that scoured the adjacent region down to bare rock. Pumice rock that covered the area is eroding down to smaller gravel. This situation represents _____. ANSWER: Chapter 6 Reading Quiz Question 15 Part A In some ecosystems, succession increases the chance of disturbance. In these ecosystems, _____. a keystone producer a keystone herbivore a vital primary consumer a keystone predator a trophic cascade a decline in trophic level efficiency the emergence of a new ecological community a loss of a trophic level from a food web primary succession with the removal of all ecological legacies secondary succession with the removal of all ecological legacies secondary succession with several ecological legacies primary succession with several ecological legacies Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 7 5/21/2014 8:01 PM ANSWER: Chapter 6 Reading Quiz Question 12 Part A A forest is logged, leaving behind the seeds and saplings of many shrubs and trees. These seeds and saplings represent _____. ANSWER: Chapter 6 Reading Quiz Question 13 Part A During primary succession, populations of different species replace one another over time because of _____. ANSWER: Chapter 6 Reading Quiz Question 14 Part A Which one of the following represents a climax community in southern Alaska? ANSWER: ecosystems begin again with primary succession climax communities are expected climax communities may not occur disturbances usually result in virtually no ecological legacy ecological legacies a climax community primary succession pioneer species migration facilitation competition All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 9 Part A In general, _____. ANSWER: Score Summary: Your score on this assignment is 0.0%. You received 0 out of a possible total of 19 points. the group of species associated with a white spruce forest lichens and mosses that colonize exposed rock birch and alder trees herbs and a few low shrubs that replace lichens and mosses food webs usually have 8-10 trophic levels food webs are interconnected food chains food chains consist of many interrelated food webs food webs consist of either consumers or producers Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 7 5/21/2014 8:01 PM

info@checkyourstudy.com
Figure 1: Examples of the 16-puzzle. The 16-puzzle consists of 15 tiles containing the numbers 1; 2; : : : ; 15 in a 4  4 grid, with an empty space left by the missing 16th tile. The goal of the 16-puzzle is to rearrange the tiles into order by sliding tiles to occupy an empty space. Figure 1 shows a sample board along with the goal con guration where the tiles are in order. A similar puzzle can be devised for any n  n board. On a board with N positions (including the empty space), the total number of possible con gurations is N!, since every arrangement of tiles can be encoded by a permutation of f1; : : : ;Ng (where the empty space is treated as an invisible tile marked with N), although some con gurations cannot be solved. The game graph for the N-puzzle contains vertices for each possible board, and an undirected edge connects every pair of boards which can be transformed into each other by one move. Since every move is reversible (that is, we can always move a tile back after the initial move), there is no need for directed edges. The game graph for the 4-puzzle contains only 4! = 24 states, and is shown in gure 2. The goal state is framed in green. The 9-puzzle has 9! = 362880 states, so it is possible to compute and store the entire game graph on a current machine. Graph algorithms can then be used to nd solutions to each board. For example, a path from a given board b to the goal con guration g (in which all tiles are in order and the empty space is at the lower right) represents a sequence of valid moves which solve b. If g is not reachable from b, then b has no solution. In general, the game graph of a puzzle may have several di erent connected components, and there may not be a goal state in each component. The game graph for an N-puzzle always has two components, and there is only one goal state. Algorithms for nding connected components can be used to nd all solvable con gurations of a puzzle. For the N-puzzle, it is also possible to determine whether a given board is solvable without traversing the game graph by using techniques from permutation theory (which is beyond the scope of this course). Figure 3 shows the neighbourhood of the goal state of the 9-puzzle. Algorithm 27 gives pseu- docode to build the game graph of an N puzzle. 1 Figure 2: The entire game graph for the 4-puzzle, with the goal state framed in green. Figure 3: A subset of the game graph for the 9-puzzle, with the goal state framed in green. 2 3

Figure 1: Examples of the 16-puzzle. The 16-puzzle consists of 15 tiles containing the numbers 1; 2; : : : ; 15 in a 4  4 grid, with an empty space left by the missing 16th tile. The goal of the 16-puzzle is to rearrange the tiles into order by sliding tiles to occupy an empty space. Figure 1 shows a sample board along with the goal con guration where the tiles are in order. A similar puzzle can be devised for any n  n board. On a board with N positions (including the empty space), the total number of possible con gurations is N!, since every arrangement of tiles can be encoded by a permutation of f1; : : : ;Ng (where the empty space is treated as an invisible tile marked with N), although some con gurations cannot be solved. The game graph for the N-puzzle contains vertices for each possible board, and an undirected edge connects every pair of boards which can be transformed into each other by one move. Since every move is reversible (that is, we can always move a tile back after the initial move), there is no need for directed edges. The game graph for the 4-puzzle contains only 4! = 24 states, and is shown in gure 2. The goal state is framed in green. The 9-puzzle has 9! = 362880 states, so it is possible to compute and store the entire game graph on a current machine. Graph algorithms can then be used to nd solutions to each board. For example, a path from a given board b to the goal con guration g (in which all tiles are in order and the empty space is at the lower right) represents a sequence of valid moves which solve b. If g is not reachable from b, then b has no solution. In general, the game graph of a puzzle may have several di erent connected components, and there may not be a goal state in each component. The game graph for an N-puzzle always has two components, and there is only one goal state. Algorithms for nding connected components can be used to nd all solvable con gurations of a puzzle. For the N-puzzle, it is also possible to determine whether a given board is solvable without traversing the game graph by using techniques from permutation theory (which is beyond the scope of this course). Figure 3 shows the neighbourhood of the goal state of the 9-puzzle. Algorithm 27 gives pseu- docode to build the game graph of an N puzzle. 1 Figure 2: The entire game graph for the 4-puzzle, with the goal state framed in green. Figure 3: A subset of the game graph for the 9-puzzle, with the goal state framed in green. 2 3

No expert has answered this question yet. You can browse … Read More...
Essay – Athlete’s high salaries. Should they be paid that amount or not?

Essay – Athlete’s high salaries. Should they be paid that amount or not?

Athlete’s high salaries: Should they be paid that amount or … Read More...
two current carrying wires . wire # 1carries a current I into the page . wire #2 carries a current I eighter into or out of page. If the net magnetic field at point A to the left . 1) I is in and I>I, 2) I is out and I>I, 3) I is in and I<I, 4) I is out and I<I, 5) I=I

two current carrying wires . wire # 1carries a current I into the page . wire #2 carries a current I eighter into or out of page. If the net magnetic field at point A to the left . 1) I is in and I>I, 2) I is out and I>I, 3) I is in and I<I, 4) I is out and I<I, 5) I=I

New York Project The assignment is to write a five paragraph paper in which you plan a theatre trip to New York City to see FOUR shows. To complete this work, use internet sources, the most thorough of which is the New York Times Theater section (see below for this and other options). The first paragraph should explain the trip’s rationale, who will be going with you (church group, theatre group, friends, etc), and a proposed budget. You should then find possible flights and hotel accommodations. In each subsequent paragraph (paragraphs 2, 3, 4, and 5), name the shows (four in total—one per paragraph) you have decided to see. Include in each paragraph the reason you have chosen to see this particular show. You will need to quote portions of reviews, both professional and reader’s, as part of your justification for your choice. Be sure to cite the name of the reviewer as well as the source from which the review was found. (Example: Ben Brantley of the New York Times calls Shrek the Musical, “Quote from review.”— or similar format.) It is not necessary to provide a “Works Cited” page, but you must reference your source within your paper as noted in the previous sentence. You must also include ticket prices and the theater where the show is playing, as well as any other pertinent information (such as a prominent actor in the cast, etc.). Be sure to follow your budget; try not to plan to see four Broadway musicals as this could eat up your budget very quickly. Mix and match with Off and Off Off Broadway, where the tickets are cheaper. Try to find at least one or two shows you have never heard of but which sound interesting because of your research into the reviews. Sources for research: New York Times page at www.nytimes.com. Select the “Arts” section (left menu). On the Arts page, select THEATER (menu near top of page). On the THEATER page, you can click on the Broadway, Off Broadway, & Off Off Broadway headings (menu near top of page), which will provide you with a list of what’s playing. Click on the show title to gain access to information such as the show’s location, ticket prices, and links to reviews, both professional and reader’s.

New York Project The assignment is to write a five paragraph paper in which you plan a theatre trip to New York City to see FOUR shows. To complete this work, use internet sources, the most thorough of which is the New York Times Theater section (see below for this and other options). The first paragraph should explain the trip’s rationale, who will be going with you (church group, theatre group, friends, etc), and a proposed budget. You should then find possible flights and hotel accommodations. In each subsequent paragraph (paragraphs 2, 3, 4, and 5), name the shows (four in total—one per paragraph) you have decided to see. Include in each paragraph the reason you have chosen to see this particular show. You will need to quote portions of reviews, both professional and reader’s, as part of your justification for your choice. Be sure to cite the name of the reviewer as well as the source from which the review was found. (Example: Ben Brantley of the New York Times calls Shrek the Musical, “Quote from review.”— or similar format.) It is not necessary to provide a “Works Cited” page, but you must reference your source within your paper as noted in the previous sentence. You must also include ticket prices and the theater where the show is playing, as well as any other pertinent information (such as a prominent actor in the cast, etc.). Be sure to follow your budget; try not to plan to see four Broadway musicals as this could eat up your budget very quickly. Mix and match with Off and Off Off Broadway, where the tickets are cheaper. Try to find at least one or two shows you have never heard of but which sound interesting because of your research into the reviews. Sources for research: New York Times page at www.nytimes.com. Select the “Arts” section (left menu). On the Arts page, select THEATER (menu near top of page). On the THEATER page, you can click on the Broadway, Off Broadway, & Off Off Broadway headings (menu near top of page), which will provide you with a list of what’s playing. Click on the show title to gain access to information such as the show’s location, ticket prices, and links to reviews, both professional and reader’s.