1. Which of the following statements for electric field lines are true? (Give ALL correct answers, i.e., B, AC, BCD…) A) E-field lines point inward toward negative charges. B) E-field lines may cross. C) E-field lines do not begin or end in a charge-free region (except at infinity). D) Where the E-field lines are dense the E-field must be weak. E) E-field lines make circles around positive charges. F) A point charge q, released from rest will initially move along an E-field line. G) E-field lines point outward from positive charges. 2. Consider two uniformly charged parallel plates as shown above. The magnitudes of the charges are equal. (For each statement select T True, F False). A) If the plates are oppositely charged, there is no electric field at c. B) If both plates are negatively charged, the electric field at a points towards the top of the page. C) If both plates are positively charged, there is no electric field at b. 3. As shown in the figure above, a ball of mass 1.050 g and positive charge q =38.1microC is suspended on a string of negligible mass in a uniform electric field. We observe that the ball hangs at an angle of theta=15.0° from the vertical. What is the magnitude of the electric field?

1. Which of the following statements for electric field lines are true? (Give ALL correct answers, i.e., B, AC, BCD…) A) E-field lines point inward toward negative charges. B) E-field lines may cross. C) E-field lines do not begin or end in a charge-free region (except at infinity). D) Where the E-field lines are dense the E-field must be weak. E) E-field lines make circles around positive charges. F) A point charge q, released from rest will initially move along an E-field line. G) E-field lines point outward from positive charges. 2. Consider two uniformly charged parallel plates as shown above. The magnitudes of the charges are equal. (For each statement select T True, F False). A) If the plates are oppositely charged, there is no electric field at c. B) If both plates are negatively charged, the electric field at a points towards the top of the page. C) If both plates are positively charged, there is no electric field at b. 3. As shown in the figure above, a ball of mass 1.050 g and positive charge q =38.1microC is suspended on a string of negligible mass in a uniform electric field. We observe that the ball hangs at an angle of theta=15.0° from the vertical. What is the magnitude of the electric field?

info@checkyourstudy.com 1.  Which of the following statements for electric field … Read More...
CHM114: Exam #3 CHM 114 Exam #3 Practice Exam (Chapters 9.1-9.4, 9.6, 10, 11.1-11.6, 13.1-13.5) Instructor: O. Graudejus Points: 100 Print Name Sign Name Student I.D. # 1. You are responsible for the information on this page. Please read it carefully. 2. If you enter your ASU ID incorrectly on the scantron, a 3 point penalty will be assessed. 3. Code your name and 10 digit affiliate identification number on the separate scantron answer sheet. Use only a #2 pencil 4. Do all calculations on the exam pages. Do not make any unnecessary marks on the answer sheet. 5. This exam consists of 25 multiple choice questions worth 4 points each and a periodic table. Make sure you have them all. 6. Choose the best answer to each of the questions and answer it on the computer-graded answer sheet. Read all responses before making a selection. 7. Read the directions carefully for each problem. 8. Avoid even casual glances at other students’ exams. 9. Stop writing and hand in your scantron answer sheet and your test promptly when instructed. LATE EXAMS MAY HAVE POINTS DEDUCTED. 10. You will have 50 minutes to complete the exam. 11. If you leave early, please do so quietly. 12. Work the easiest problems first. 13. A periodic table is attached as the last page to this exam. 14. Answers will be posted online this afternoon. Potentially useful information: K = ºC + 273.15 PV=nRT R=8.314 J·K-1·mol-1 DE = q + w 760 torr = 1 atm = 101325 Pa = 1.013 bar Avogadro’s Number = 6.022 × 1023 particles/mole q = (Sp. Heat) × m × DT (Specific Heatwater = 4.184 J/g°C) 1 2 2 3 2 ( is a constant) KE mv KE RT R = = M RT u 3 = \ -2- CHM 114: Exam #3 1) Of the following molecules, only __________ is polar. A) CCl4 B) BCl3 C) NCl3 D) BeCl2 E) Cl2 2) The molecular geometry of the CHF3 molecule is __________, and the molecule is __________. A) trigonal pyramidal, polar B) tetrahedral, nonpolar C) seesaw, nonpolar D) tetrahedral, polar E) seesaw, polar 3) The electron-domain geometry of __________ is tetrahedral. A) 4 CBr B) 3 PH C) 2 2 CCl Br D) 4 XeF E) all of the above except 4 XeF 4) Of the following substances, only __________ has London dispersion forces as its only intermolecular force. A) H2O B) CCl4 C) HF D) CH3COOH E) PH3 5) The principal reason for the extremely low solubility of NaCl in benzene (C6H6) is the __________. A) strong solvent-solvent interactions B) hydrogen bonding in C6H6 C) strength of the covalent bond in NaCl D) weak solvation (interaction) of Na+ and Cl- by C6H6 E) increased disorder due to mixing of solute and solvent -3- CHM 114: Exam #3 6) There are __________  and __________  bonds in the H −C º C−H molecule. A) 3 and 2 B) 3 and 4 C) 4 and 3 D) 2 and 3 E) 5 and 0 7) A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm. A) 1.5 B) 7.5 C) 0.67 D) 3.3 E) 15 8) A mixture of He and Ne at a total pressure of 0.95 atm is found to contain 0.32 mol of He and 0.56 mol of Ne. The partial pressure of Ne is __________ atm. A) 1.7 B) 1.5 C) 0.60 D) 0.35 E) 1.0 9) Automobile air bags use the decomposition of sodium azide as their source of gas for rapid inflation: 3 2 2NaN (s)®2Na (s) + 3N (g) . What mass (g) of 3 NaN is required to provide 40.0 L of 2 N at 25.0 °C and 763 torr? A) 1.64 B) 1.09 C) 160 D) 71.1  10) The reaction of 50 mL of 2 Cl gas with 50 mL of 4 CH gas via the equation: 2 4 3 Cl (g) + CH (g)®HCl (g) + CH Cl (g) will produce a total of __________ mL of products if pressure and temperature are kept constant. A) 100 B) 50 C) 200 D) 150 E) 250 -4- CHM 114: Exam #3 11) The density of 2 N O at 1.53 atm and 45.2 °C is __________ g/L. A) 18.2 B) 1.76 C) 0.388 D) 9.99 E) 2.58 12) A gas at a pressure of 325 torr exerts a force of __________ N on an area of 2 5.5 m . A)1.8×103 B) 59 C) 5 2.4×10 D) 0.018 E) 2.4 13) According to kinetic-molecular theory, in which of the following gases will the root-mean-square speed of the molecules be the highest at 200 °C? A) HCl B) 2 Cl C) 2 H O D) 6 SF E) None. The molecules of all gases have the same root-mean-square speed at any given temperature. 14) A real gas will behave most like an ideal gas under conditions of __________. A) high temperature and high pressure B) high temperature and low pressure C) low temperature and high pressure D) low temperature and low pressure E) STP 15) Elemental iodine (I2) is a solid at room temperature. What is the major attractive force that exists among different I2 molecules in the solid? A) London dispersion forces B) dipole-dipole rejections C) ionic-dipole interactions D) covalent-ionic interactions E) dipole-dipole attractions -5- CHM 114: Exam #3 16) The heat of fusion of water is 6.01 kJ/mol. The heat capacity of liquid water is 75.3 Jmol-1K-1. The conversion of 50.0 g of ice at 0.00 °C to liquid water at 22.0 °C requires __________ kJ of heat. A) 3.8×102 B) 21.3 C) 17.2 D) 0.469 E) Insufficient data are given. 17) Of the following substances, __________ has the highest boiling point. A) 2 H O B) 2 CO C) 4 CH D) Kr E) SF4 18) Which statements about viscosity are true? (i) Viscosity increases as temperature decreases. (ii) Viscosity increases as molecular weight increases. (iii) Viscosity increases as intermolecular forces increase. A) (i) only B) (ii) and (iii) C) (i) and (iii) D) none E) all 19) Based on molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point? A) 3 2 3 CH CH CH B) 3 3 CH OCH C) 3 CH Cl D) 3 CH CHO E) 3 CH CN -6- CHM 114: Exam #3 20) On the phase diagram shown above, the coordinates of point __________ correspond to the critical temperature and pressure. A) A B) B C) C D) D E) E 21) The vapor pressure of pure ethanol at 60 °C is 0.459 atm. Raoult’s Law predicts that a solution prepared by dissolving 10.0 mmol naphthalene (nonvolatile) in 90.0 mmol ethanol will have a vapor pressure of _______ atm. A) 0.498 B) 0.413 C) 0.790 D) 0.367 E) 0.0918 Of the following, a 0.1 M aqueous solution of __________ will have the highest freezing point. A) NaCl B) Al(NO3)3 C) K2CrO4 D) Na2SO4 E) sucrose (a sugar) 23) What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula weight = 164 g/mol) in 115 g of water? The molal freezing point depression constant for water is 1.86 °C/m. A) -3.34 B) -1.11 C) 3.34 D) 1.11 E) 0.00 -7- CHM 114: Exam #3 24) The phase changes B  C and D  E are not associated with temperature increases because the heat energy is used up to __________. A) break intermolecular bonds B) break intramolecular bonds C) rearrange atoms within molecules D) increase the velocity of molecules E) increase the density of the sample 25) Ammonium nitrate (NH4NO3) dissolves readily in water even though the dissolution is endothermic by 26.4 kJ/mol. The solution process is spontaneous because __________. A) the vapor pressure of the water decreases upon addition of the solute B) the ammonium and the nitrate ion both contain nitrogen C) of the decrease in enthalpy upon addition of the solute D) of the increase in enthalpy upon dissolution of this strong electrolyte E) of the increase in disorder (entropy) upon dissolution of this strong electrolyte    -8- CHM 114: Exam #3

CHM114: Exam #3 CHM 114 Exam #3 Practice Exam (Chapters 9.1-9.4, 9.6, 10, 11.1-11.6, 13.1-13.5) Instructor: O. Graudejus Points: 100 Print Name Sign Name Student I.D. # 1. You are responsible for the information on this page. Please read it carefully. 2. If you enter your ASU ID incorrectly on the scantron, a 3 point penalty will be assessed. 3. Code your name and 10 digit affiliate identification number on the separate scantron answer sheet. Use only a #2 pencil 4. Do all calculations on the exam pages. Do not make any unnecessary marks on the answer sheet. 5. This exam consists of 25 multiple choice questions worth 4 points each and a periodic table. Make sure you have them all. 6. Choose the best answer to each of the questions and answer it on the computer-graded answer sheet. Read all responses before making a selection. 7. Read the directions carefully for each problem. 8. Avoid even casual glances at other students’ exams. 9. Stop writing and hand in your scantron answer sheet and your test promptly when instructed. LATE EXAMS MAY HAVE POINTS DEDUCTED. 10. You will have 50 minutes to complete the exam. 11. If you leave early, please do so quietly. 12. Work the easiest problems first. 13. A periodic table is attached as the last page to this exam. 14. Answers will be posted online this afternoon. Potentially useful information: K = ºC + 273.15 PV=nRT R=8.314 J·K-1·mol-1 DE = q + w 760 torr = 1 atm = 101325 Pa = 1.013 bar Avogadro’s Number = 6.022 × 1023 particles/mole q = (Sp. Heat) × m × DT (Specific Heatwater = 4.184 J/g°C) 1 2 2 3 2 ( is a constant) KE mv KE RT R = = M RT u 3 = \ -2- CHM 114: Exam #3 1) Of the following molecules, only __________ is polar. A) CCl4 B) BCl3 C) NCl3 D) BeCl2 E) Cl2 2) The molecular geometry of the CHF3 molecule is __________, and the molecule is __________. A) trigonal pyramidal, polar B) tetrahedral, nonpolar C) seesaw, nonpolar D) tetrahedral, polar E) seesaw, polar 3) The electron-domain geometry of __________ is tetrahedral. A) 4 CBr B) 3 PH C) 2 2 CCl Br D) 4 XeF E) all of the above except 4 XeF 4) Of the following substances, only __________ has London dispersion forces as its only intermolecular force. A) H2O B) CCl4 C) HF D) CH3COOH E) PH3 5) The principal reason for the extremely low solubility of NaCl in benzene (C6H6) is the __________. A) strong solvent-solvent interactions B) hydrogen bonding in C6H6 C) strength of the covalent bond in NaCl D) weak solvation (interaction) of Na+ and Cl- by C6H6 E) increased disorder due to mixing of solute and solvent -3- CHM 114: Exam #3 6) There are __________  and __________  bonds in the H −C º C−H molecule. A) 3 and 2 B) 3 and 4 C) 4 and 3 D) 2 and 3 E) 5 and 0 7) A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm. A) 1.5 B) 7.5 C) 0.67 D) 3.3 E) 15 8) A mixture of He and Ne at a total pressure of 0.95 atm is found to contain 0.32 mol of He and 0.56 mol of Ne. The partial pressure of Ne is __________ atm. A) 1.7 B) 1.5 C) 0.60 D) 0.35 E) 1.0 9) Automobile air bags use the decomposition of sodium azide as their source of gas for rapid inflation: 3 2 2NaN (s)®2Na (s) + 3N (g) . What mass (g) of 3 NaN is required to provide 40.0 L of 2 N at 25.0 °C and 763 torr? A) 1.64 B) 1.09 C) 160 D) 71.1  10) The reaction of 50 mL of 2 Cl gas with 50 mL of 4 CH gas via the equation: 2 4 3 Cl (g) + CH (g)®HCl (g) + CH Cl (g) will produce a total of __________ mL of products if pressure and temperature are kept constant. A) 100 B) 50 C) 200 D) 150 E) 250 -4- CHM 114: Exam #3 11) The density of 2 N O at 1.53 atm and 45.2 °C is __________ g/L. A) 18.2 B) 1.76 C) 0.388 D) 9.99 E) 2.58 12) A gas at a pressure of 325 torr exerts a force of __________ N on an area of 2 5.5 m . A)1.8×103 B) 59 C) 5 2.4×10 D) 0.018 E) 2.4 13) According to kinetic-molecular theory, in which of the following gases will the root-mean-square speed of the molecules be the highest at 200 °C? A) HCl B) 2 Cl C) 2 H O D) 6 SF E) None. The molecules of all gases have the same root-mean-square speed at any given temperature. 14) A real gas will behave most like an ideal gas under conditions of __________. A) high temperature and high pressure B) high temperature and low pressure C) low temperature and high pressure D) low temperature and low pressure E) STP 15) Elemental iodine (I2) is a solid at room temperature. What is the major attractive force that exists among different I2 molecules in the solid? A) London dispersion forces B) dipole-dipole rejections C) ionic-dipole interactions D) covalent-ionic interactions E) dipole-dipole attractions -5- CHM 114: Exam #3 16) The heat of fusion of water is 6.01 kJ/mol. The heat capacity of liquid water is 75.3 Jmol-1K-1. The conversion of 50.0 g of ice at 0.00 °C to liquid water at 22.0 °C requires __________ kJ of heat. A) 3.8×102 B) 21.3 C) 17.2 D) 0.469 E) Insufficient data are given. 17) Of the following substances, __________ has the highest boiling point. A) 2 H O B) 2 CO C) 4 CH D) Kr E) SF4 18) Which statements about viscosity are true? (i) Viscosity increases as temperature decreases. (ii) Viscosity increases as molecular weight increases. (iii) Viscosity increases as intermolecular forces increase. A) (i) only B) (ii) and (iii) C) (i) and (iii) D) none E) all 19) Based on molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point? A) 3 2 3 CH CH CH B) 3 3 CH OCH C) 3 CH Cl D) 3 CH CHO E) 3 CH CN -6- CHM 114: Exam #3 20) On the phase diagram shown above, the coordinates of point __________ correspond to the critical temperature and pressure. A) A B) B C) C D) D E) E 21) The vapor pressure of pure ethanol at 60 °C is 0.459 atm. Raoult’s Law predicts that a solution prepared by dissolving 10.0 mmol naphthalene (nonvolatile) in 90.0 mmol ethanol will have a vapor pressure of _______ atm. A) 0.498 B) 0.413 C) 0.790 D) 0.367 E) 0.0918 Of the following, a 0.1 M aqueous solution of __________ will have the highest freezing point. A) NaCl B) Al(NO3)3 C) K2CrO4 D) Na2SO4 E) sucrose (a sugar) 23) What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula weight = 164 g/mol) in 115 g of water? The molal freezing point depression constant for water is 1.86 °C/m. A) -3.34 B) -1.11 C) 3.34 D) 1.11 E) 0.00 -7- CHM 114: Exam #3 24) The phase changes B  C and D  E are not associated with temperature increases because the heat energy is used up to __________. A) break intermolecular bonds B) break intramolecular bonds C) rearrange atoms within molecules D) increase the velocity of molecules E) increase the density of the sample 25) Ammonium nitrate (NH4NO3) dissolves readily in water even though the dissolution is endothermic by 26.4 kJ/mol. The solution process is spontaneous because __________. A) the vapor pressure of the water decreases upon addition of the solute B) the ammonium and the nitrate ion both contain nitrogen C) of the decrease in enthalpy upon addition of the solute D) of the increase in enthalpy upon dissolution of this strong electrolyte E) of the increase in disorder (entropy) upon dissolution of this strong electrolyte    -8- CHM 114: Exam #3

PHY-102: Energy and Circular Motion Exercises Complete the following exercises. 1. A rifle with a longer barrel can fire bullets with a larger velocity than a rifle with a shorter barrel. a. Explain this using the impulse-momentum theorem. b. Explain this using the work-energy theorem 2. Use physics terms to explain the benefits of crumple zones in modern cars. 3. When a gun is fired at the shooting range, the gun recoils (moves backward). Explain this using the law of conservation of momentum. 4. Rank the following in terms of increasing inertia: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 5. Rank the following in terms of increasing momentum: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 6. Rank the following in terms of increasing kinetic energy: A. A 1200 kg car going 15 m/s B. A 10,000 kg train car at rest C. A 15 kg meteor going at a speed of 1000 m/s D. A 100 kg person running at 5 m/s 7. Ben (55 kg) is standing on very slippery ice when Junior (25 kg) bumps into him. Junior was moving at a speed of 8 m/s before the collision and Ben and Junior embrace after the collision. Find the speed of Ben and Junior as they move across the ice after the collision. Give the answer in m/s. Describe the work you did to get the answer. 8. Identical marbles are released from the same height on each of the following four frictionless ramps. Compare the speed of the marbles at the end of each ramp. Explain your reasoning. 9. A force of only 150 N can lift a 600 N sack of flour to a height of 0.50 m when using a lever as shown in the diagram below. a. Find the work done on the sack of flour (in J). b. Find the distance you must push with the 150 N force on the left side (in m). c. Briefly explain the benefit of using a lever to lift a heavy object. 10. Rank the following in terms of increasing power. A. Doing 100 J of work in 10 seconds. B. Doing 100 J of work in 5 seconds. C. Doing 200 J of work in 5 seconds. D. Doing 400 J of work in 30 seconds. 11. A student lifts a 25 kg mass a vertical distance of 1.6 m in a time of 2.0 seconds. a. Find the force needed to lift the mass (in N). b. Find the work done by the student (in J). c. Find the power exerted by the student (in W). 12. A satellite is put into an orbit at a distance from the center of the Earth equal to twice the distance from the center of the Earth to the surface. If the satellite had a weight at the surface of 4000 N, what is the force of gravity (weight) of the satellite when it is in its orbit? Give your answer in newtons, N. 13. Consider a satellite in a circular orbit around the Earth. a. Why is it important to give a satellite a horizontal speed when placing it in orbit? b. What will happen if the horizontal speed is too small? c. What will happen if the horizontal speed is too large? 14. If you drop an object from a distance of 1 meter above the ground, where would it fall to the ground in the shortest time: Atop Mt. Everest or in New York? 15. Why do the astronauts aboard the space station appear to be weightless? 16. Why do the passengers on a high-flying airplane not appear weightless, similar to the astronauts on the space station? 17. A ranger needs to capture a monkey hanging on a tree branch. The ranger aims his dart gun directly at the monkey and fires the tranquilizer dart. However, the monkey lets go of the branch at exactly the same time as the ranger fires the dart. Will the monkey get hit or will it avoid the dart? The remaining questions are multiple-choice questions: 18. Compared to its weight on Earth, a 5 kg object on the moon will weigh A. the same amount. B. less. C. more. 19. Compared to its mass on Earth, a 5 kg object on the moon will have A. the same mass. B. less mass. C. more mass. 20. The reason padded dashboards are used in cars is that they A. look nice and feel good. B. decrease the impulse in a collision. C. increase the force of impact in a collision. D. decrease the momentum of a collision. E. increase the time of impact in a collision. 21. Suppose you are standing on a frozen lake where there is no friction between your feet and the ice. What can you do to get off the lake? A. Bend over touching the ice in front of you and then bring you feet to your hands. B. Walk very slowly on tiptoe. C. Get on your hands and knees and crawl off the ice. D. Throw something in the direction opposite to the way you want to go. 22. A car travels in a circle with constant speed. Which of the following is true? A. The net force on the car is zero because the car is not accelerating. B. The net force on the car is directed forward, in the direction of travel. C. The net force on the car is directed inward, toward the center of the curve. D. The net force on the car is directed outward, away from the center of the curve. 23. A job is done slowly, and an identical job is done quickly. Which of the following is true? a. They require the same amount of force, but different amounts of work. b. They require the same amount of work, but different amounts of power. c. They require the same amounts of power, but different amounts of work. d. They require the same amounts of work, but different amounts of energy. 24. How many joules of work are done on a box when a force of 60 N pushes it 5 m in 3 seconds? a. 300 J b. 12 J c. 100 J d. 36 J e. 4 J 25. A 1 kg cart moving with a speed of 3 m/s collides with a 2 kg cart at rest. If the carts stick together after the collision, with what speed will they move after the collision? a. 3 m/s b. 1.5 m/s c. 1 m/s d. 2 m/s

PHY-102: Energy and Circular Motion Exercises Complete the following exercises. 1. A rifle with a longer barrel can fire bullets with a larger velocity than a rifle with a shorter barrel. a. Explain this using the impulse-momentum theorem. b. Explain this using the work-energy theorem 2. Use physics terms to explain the benefits of crumple zones in modern cars. 3. When a gun is fired at the shooting range, the gun recoils (moves backward). Explain this using the law of conservation of momentum. 4. Rank the following in terms of increasing inertia: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 5. Rank the following in terms of increasing momentum: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 6. Rank the following in terms of increasing kinetic energy: A. A 1200 kg car going 15 m/s B. A 10,000 kg train car at rest C. A 15 kg meteor going at a speed of 1000 m/s D. A 100 kg person running at 5 m/s 7. Ben (55 kg) is standing on very slippery ice when Junior (25 kg) bumps into him. Junior was moving at a speed of 8 m/s before the collision and Ben and Junior embrace after the collision. Find the speed of Ben and Junior as they move across the ice after the collision. Give the answer in m/s. Describe the work you did to get the answer. 8. Identical marbles are released from the same height on each of the following four frictionless ramps. Compare the speed of the marbles at the end of each ramp. Explain your reasoning. 9. A force of only 150 N can lift a 600 N sack of flour to a height of 0.50 m when using a lever as shown in the diagram below. a. Find the work done on the sack of flour (in J). b. Find the distance you must push with the 150 N force on the left side (in m). c. Briefly explain the benefit of using a lever to lift a heavy object. 10. Rank the following in terms of increasing power. A. Doing 100 J of work in 10 seconds. B. Doing 100 J of work in 5 seconds. C. Doing 200 J of work in 5 seconds. D. Doing 400 J of work in 30 seconds. 11. A student lifts a 25 kg mass a vertical distance of 1.6 m in a time of 2.0 seconds. a. Find the force needed to lift the mass (in N). b. Find the work done by the student (in J). c. Find the power exerted by the student (in W). 12. A satellite is put into an orbit at a distance from the center of the Earth equal to twice the distance from the center of the Earth to the surface. If the satellite had a weight at the surface of 4000 N, what is the force of gravity (weight) of the satellite when it is in its orbit? Give your answer in newtons, N. 13. Consider a satellite in a circular orbit around the Earth. a. Why is it important to give a satellite a horizontal speed when placing it in orbit? b. What will happen if the horizontal speed is too small? c. What will happen if the horizontal speed is too large? 14. If you drop an object from a distance of 1 meter above the ground, where would it fall to the ground in the shortest time: Atop Mt. Everest or in New York? 15. Why do the astronauts aboard the space station appear to be weightless? 16. Why do the passengers on a high-flying airplane not appear weightless, similar to the astronauts on the space station? 17. A ranger needs to capture a monkey hanging on a tree branch. The ranger aims his dart gun directly at the monkey and fires the tranquilizer dart. However, the monkey lets go of the branch at exactly the same time as the ranger fires the dart. Will the monkey get hit or will it avoid the dart? The remaining questions are multiple-choice questions: 18. Compared to its weight on Earth, a 5 kg object on the moon will weigh A. the same amount. B. less. C. more. 19. Compared to its mass on Earth, a 5 kg object on the moon will have A. the same mass. B. less mass. C. more mass. 20. The reason padded dashboards are used in cars is that they A. look nice and feel good. B. decrease the impulse in a collision. C. increase the force of impact in a collision. D. decrease the momentum of a collision. E. increase the time of impact in a collision. 21. Suppose you are standing on a frozen lake where there is no friction between your feet and the ice. What can you do to get off the lake? A. Bend over touching the ice in front of you and then bring you feet to your hands. B. Walk very slowly on tiptoe. C. Get on your hands and knees and crawl off the ice. D. Throw something in the direction opposite to the way you want to go. 22. A car travels in a circle with constant speed. Which of the following is true? A. The net force on the car is zero because the car is not accelerating. B. The net force on the car is directed forward, in the direction of travel. C. The net force on the car is directed inward, toward the center of the curve. D. The net force on the car is directed outward, away from the center of the curve. 23. A job is done slowly, and an identical job is done quickly. Which of the following is true? a. They require the same amount of force, but different amounts of work. b. They require the same amount of work, but different amounts of power. c. They require the same amounts of power, but different amounts of work. d. They require the same amounts of work, but different amounts of energy. 24. How many joules of work are done on a box when a force of 60 N pushes it 5 m in 3 seconds? a. 300 J b. 12 J c. 100 J d. 36 J e. 4 J 25. A 1 kg cart moving with a speed of 3 m/s collides with a 2 kg cart at rest. If the carts stick together after the collision, with what speed will they move after the collision? a. 3 m/s b. 1.5 m/s c. 1 m/s d. 2 m/s

info@checkyourstudy.com
FSE 100 Extra Credit (20 points) Instructions: Read the description below and work through the design process to build an automated waste sorting system. Turn in the following deliverables in one document, typed: 1. Problem Statement – 1 point 2. Technical System Requirements (at least 3 complete sentences using “shall”) – 3 points 3. Judging Criteria (at least 3, explain why you chose them) – 2 points 4. AHP – 2 points 5. Summaries of your 3 design options (paragraph minimum for each option) – 3 points 6. Design Decision Matrix – 3 points 7. Orthographic Drawing of your final design (3 projections required) – 3 points 8. Activity Diagram of how your sorter functions – 3 points Description: The city of Tempe waste management has notified ASU that due to the exceptional effort the Sundevil students have made in the sustainability area, ASU has been contributing three times the amount of recyclable materials than what was predicted on a monthly basis. Unfortunately, due to the immense amount of materials being delivered, the city of Tempe waste management has asked for assistance from ASU prior to picking up the recyclable waste. They have requested that ASU implement an automated waste sorting system that would pre-filter all the materials so the city of Tempe can collect the materials based on one of three types and process the waste much faster. ASU has hired you to design an automated sorter, but due to the unexpected nature of this request, ASU prefers that this design be as simple and inexpensive to build as possible. The city of Tempe would like to have the waste categorized as either glass, plastic, or metal. Paper will not be considered in this design. Any glass that is sorted in your device needs to stay intact, and not break. Very few people will be able to monitor this device as it sorts, so it must be able to sort the items with no input from a user, as quickly as possible. This design cannot exceed 2m in length, width, or height, but the weight is unlimited. ASU is not giving any guidance as to the materials you can use, so you are free to shop for whatever you’d like, but keep in mind, the final cost of this device must be as inexpensive as possible. Submit through Blackboard or print out your document and turn it in to me no later than the date shown on Blackboard.

FSE 100 Extra Credit (20 points) Instructions: Read the description below and work through the design process to build an automated waste sorting system. Turn in the following deliverables in one document, typed: 1. Problem Statement – 1 point 2. Technical System Requirements (at least 3 complete sentences using “shall”) – 3 points 3. Judging Criteria (at least 3, explain why you chose them) – 2 points 4. AHP – 2 points 5. Summaries of your 3 design options (paragraph minimum for each option) – 3 points 6. Design Decision Matrix – 3 points 7. Orthographic Drawing of your final design (3 projections required) – 3 points 8. Activity Diagram of how your sorter functions – 3 points Description: The city of Tempe waste management has notified ASU that due to the exceptional effort the Sundevil students have made in the sustainability area, ASU has been contributing three times the amount of recyclable materials than what was predicted on a monthly basis. Unfortunately, due to the immense amount of materials being delivered, the city of Tempe waste management has asked for assistance from ASU prior to picking up the recyclable waste. They have requested that ASU implement an automated waste sorting system that would pre-filter all the materials so the city of Tempe can collect the materials based on one of three types and process the waste much faster. ASU has hired you to design an automated sorter, but due to the unexpected nature of this request, ASU prefers that this design be as simple and inexpensive to build as possible. The city of Tempe would like to have the waste categorized as either glass, plastic, or metal. Paper will not be considered in this design. Any glass that is sorted in your device needs to stay intact, and not break. Very few people will be able to monitor this device as it sorts, so it must be able to sort the items with no input from a user, as quickly as possible. This design cannot exceed 2m in length, width, or height, but the weight is unlimited. ASU is not giving any guidance as to the materials you can use, so you are free to shop for whatever you’d like, but keep in mind, the final cost of this device must be as inexpensive as possible. Submit through Blackboard or print out your document and turn it in to me no later than the date shown on Blackboard.

  Problem statement      ASU has been contributing three … Read More...
STUDENT GRADER Total Score I am submitting my own work, and I understand penalties will be assessed if I submit work for credit that is not my own. Print Name ID Number Sign Name Date # Points Score 1 4 2 8 3 6 4 12 5 4 6 10 7 8 8 6 9 6 Weeks late Adjusted Score Estimated Work Hours 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Overall Weight Adjusted Score: Deduct 20% from score for each week late Problem 1. Sketch circuits for the following logic equations. Y <= (A and B and C) or not ((A and not B and C and not D) or not (B or D)); X <= (A xor (B and C) xor not D) or (not (B xor C) and not (C or D)) Problem 2. Sketch circuits and write VHDL assignment statements for the following equations. F = m(1, 2, 6) F = M(0, 7) Problem 3. Write logic assignment statements for the following circuit. Problem 4: Sketch circuits and write VHDL assignment statements for the truth tables below. Problem 5: Sketch POS circuits for the 2XOR and 2XNOR functions. Problem 6: Sketch the circuit described by the netlist shown, and complete the timing diagram for the stimulus shown to document the circuit’s response to the example stimulus. Use a 100ns vertical grid in your timing diagram, and show all inputs and outputs. Problem 7: Create a truth table that corresponds to the simulation shown below. Show all input and output values in the truth table, and sketch a logic circuit that could have been used to create the waveform. Problem 8. The Seattle Mariners haven’t had a stolen base in 6 months, and the manager decided it was because the other teams were reading his signals to the base runners. He came up with a new set of signals (pulling on his EAR, lifting one LEG, patting the top of his HEAD, and BOWing) to indicate when runners should attempt to steal a base. A runner should STEAL a base if and only if the manager pulls his EAR and BOWs while patting his HEAD, or if he lifts his LEG and pats his HEAD without BOWing, or anytime he pulls his EAR without lifting his LEG. Sketch a minimal circuit that could be used to indicate when a runner should steal a base. Problem 9. A room has four doors and four light switches (one by each door). Sketch a circuit that allows the four switches to control the light – each switch should be able to turn the light on if it is currently off, and off if it is currently on. Note that it will not be possible to associate a given switch position with “light on” or “light off” – simply moving any switch should modify the light’s status.

STUDENT GRADER Total Score I am submitting my own work, and I understand penalties will be assessed if I submit work for credit that is not my own. Print Name ID Number Sign Name Date # Points Score 1 4 2 8 3 6 4 12 5 4 6 10 7 8 8 6 9 6 Weeks late Adjusted Score Estimated Work Hours 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Overall Weight Adjusted Score: Deduct 20% from score for each week late Problem 1. Sketch circuits for the following logic equations. Y <= (A and B and C) or not ((A and not B and C and not D) or not (B or D)); X <= (A xor (B and C) xor not D) or (not (B xor C) and not (C or D)) Problem 2. Sketch circuits and write VHDL assignment statements for the following equations. F = m(1, 2, 6) F = M(0, 7) Problem 3. Write logic assignment statements for the following circuit. Problem 4: Sketch circuits and write VHDL assignment statements for the truth tables below. Problem 5: Sketch POS circuits for the 2XOR and 2XNOR functions. Problem 6: Sketch the circuit described by the netlist shown, and complete the timing diagram for the stimulus shown to document the circuit’s response to the example stimulus. Use a 100ns vertical grid in your timing diagram, and show all inputs and outputs. Problem 7: Create a truth table that corresponds to the simulation shown below. Show all input and output values in the truth table, and sketch a logic circuit that could have been used to create the waveform. Problem 8. The Seattle Mariners haven’t had a stolen base in 6 months, and the manager decided it was because the other teams were reading his signals to the base runners. He came up with a new set of signals (pulling on his EAR, lifting one LEG, patting the top of his HEAD, and BOWing) to indicate when runners should attempt to steal a base. A runner should STEAL a base if and only if the manager pulls his EAR and BOWs while patting his HEAD, or if he lifts his LEG and pats his HEAD without BOWing, or anytime he pulls his EAR without lifting his LEG. Sketch a minimal circuit that could be used to indicate when a runner should steal a base. Problem 9. A room has four doors and four light switches (one by each door). Sketch a circuit that allows the four switches to control the light – each switch should be able to turn the light on if it is currently off, and off if it is currently on. Note that it will not be possible to associate a given switch position with “light on” or “light off” – simply moving any switch should modify the light’s status.

info@checkyourstudy.com
Light from a HeNe laser (A = 632.8 nm) strikes a pair of slits at normal incidence, forming a double slit pattern on a screen 1.4 m from the slits, as shown in the figure below. What is the slit spacing?

Light from a HeNe laser (A = 632.8 nm) strikes a pair of slits at normal incidence, forming a double slit pattern on a screen 1.4 m from the slits, as shown in the figure below. What is the slit spacing?

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