MIDTERM REVIEW. What was the total distance traveled by the object during the 10.0-second time interval? A) 0 m B) 8 m C) 16 m D) 24 m

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1 NAME MIDTERM REVIEW 1. A student on an amusement park ride moves in a circular path with a radius of 3.5 meters once every 8.9 seconds. The student moves at an average speed of A) 0.39 m/s B) 1.2 m/s C) 2.5 m/s D) 4.3 m/s 2. A car travels 20. meters east in 1.0 second. The displacement of the car at the end of this 1.0-second interval is A) 20. m B) 20. m/s C) 20. m east D) 20. m/s east 3. A moving body must undergo a change of A) velocity B) acceleration C) position D) direction 4. A car travels 90. meters due north in 15 seconds. Then the car turns around and travels 40. meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20.-second interval? A) 2.5 m/s B) 5.0 m/s C) 6.5 m/s D) 7.0 m/s 5. A truck, initially traveling at a speed of 22 meters per second, increases speed at a constant rate of 2.4 meters per second 2 for 3.2 seconds. What is the total distance traveled by the truck during this 3.2-second time interval? A) 12 m B) 58 m C) 70. m D) 83 m 6. A roller coaster, traveling with an initial speed of 15 meters per second, decelerates uniformly at 7.0 meters per second 2 to a full stop. Approximately how far does the roller coaster travel during its deceleration? A) 1.0 m B) 2.0 m C) 16 m D) 32 m 7. Starting from rest, an object rolls freely down an incline that is 10 meters long in 2 seconds. The acceleration of the object is approximately A) 5 m/sec B) 5 m/sec 2 C) 10 m/sec D) 10 m/sec 2 8. A child riding a bicycle at 15 meters per second accelerates at -3.0 meters per second 2 for 4.0 seconds. What is the child s speed at the end of this 4.0-second interval? A) 12 m/s B) 27 m/s C) 3.0 m/s D) 7.0 m/s 9. A rock is dropped from a bridge. What happens to the magnitude of the acceleration and the speed of the rock as it falls? [Neglect friction.] A) Both acceleration and speed increase. B) Both acceleration and speed remain the same. C) Acceleration increases and speed decreases. D) Acceleration remains the same and speed increases. 10. A rock dropped off a bridge takes 5 seconds to hit the water. Approximately what was the rock's velocity just before impact? A) 5 m/s B) 2 m/s C) 50 m/s D) 125 m/s 11. A ball is thrown straight downward with a speed of 0.50 meter per second from a height of 4.0 meters. What is the speed of the ball 0.70 second after it is released? [Neglect friction.] A) 0.50 m/s B) 7.4 m/s C) 9.8 m/s D) 15 m/s 12. A rock falls from rest a vertical distance of 0.72 meter to the surface of a planet in 0.63 second. The magnitude of the acceleration due to gravity on the planet is A) 1.1 m/s 2 B) 2.3 m/s 2 C) 3.6 m/s 2 D) 9.8 m/s The graph below represents the displacement of an object moving in a straight line as a function of time. What was the total distance traveled by the object during the 10.0-second time interval? A) 0 m B) 8 m C) 16 m D) 24 m

2 14. Which graph best represents the motion of an object whose speed is increasing? A) B) C) D) 15. Base your answer to the following question on the graph below, which represents the relationship between the displacement of an object and its time of travel along a straight line. What is the magnitude of the object's total displacement after 8.0 seconds? A) 0 m B) 2 m C) 8 m D) 16 m Base your answers to questions 16 through 20 on the graph below which represents the displacement of an object as a function of time. 16. How far is the object from the starting point at the end of 3 seconds? A) 0 m B) 2.0 m C) 3.0 m D) 9.0 m 17. What is the velocity of the object at t = 1 second? A) 1.0 m/s B) 2.0 m/s C) 3.0 m/s D) 1.5 m/s 18. During which time interval is the object at rest? A) 0-2 s B) 2-3 s C) 3-4 s D) 4-6 s

3 19. What is the average velocity of the object from t = 0 to t = 3 seconds? A) 1.0 m/s B) 2.0 m/s C) 3.0 m/s D) 0 m/s 20. During which time interval is the object accelerating? A) 0-2 s B) 2-3 s C) 3-4 s D) 4-6 s Base your answers to questions 21 through 26 on the graph below which represents the relationship between speed and time for an object in motion along a straight line. 21. What is the acceleration of the object during the time interval t = 3 seconds to t = 5 seconds? A) 5.0 m/sec 2 B) 7.5 m/sec 2 C) 12.5 m/sec 2 D) 17.5 m/sec What is the average speed of the object during the time interval t = 6 seconds to t = 8 seconds'? A) 7.5 m/sec B) 10 m/sec C) 15 m/sec D) 17.5 m/sec 23. What is the total distance traveled by the object during the first 3 seconds? A) 15 m B) 20 m C) 25 m D) 30 m 24. During which interval is the object's acceleration the greatest? A) AB B) CD C) DE D) EF 25. During the interval t = 8 seconds to t = 10 seconds, the speed of the object is A) zero B) increasing C) decreasing D) constant, but not zero 26. What is the maximum speed reached by the object during the 10 seconds of travel? A) 10 m/sec B) 25 m/sec C) 150 m/sec D) 250 m/sec 27. What is the momentum of a kilogram car as it travels at 30. meters per second due east for 60. seconds? A) kg m/s, east B) kg m/s, west C) kg m, east D) kg m, west 28. An object traveling at 4.0 meters per second has a momentum of 16 kilogram-meters per second. What is the mass of the object? A) 64 kg B) 20 kg C) 12 kg D) 4.0 kg

4 29. An air bag is used to safely decrease the momentum of a driver in a car accident. The air bag reduces the magnitude of the force acting on the driver by A) increasing the length of time the force acts on the driver B) decreasing the distance over which the force acts on the driver C) increasing the rate of acceleration of the driver D) decreasing the mass of the driver 30. A 3.0-kilogram object is acted upon by an impulse having a magnitude of 15 newton seconds. What is the magnitude of the object s change in momentum due to this impulse? A) 5.0 kg m/s B) 15 kg m/s C) 3.0 kg m/s D) 45 kg m/s 31. Which quantity has both a magnitude and a direction? A) energy B) impulse C) power D) work 32. A 75-kilogram hockey player is skating across the ice at a speed of 6.0 meters per second. What is the magnitude of the average force required to stop the player in 0.65 second? A) 120 N B) 290 N C) 690 N D) 920 N 33. Which situation will produce the greatest change of momentum for a 1.0-kilogram cart? A) accelerating it from rest to 3.0 m/s B) accelerating it from 2.0 m/s to 4.0 m/s C) applying a net force of 5.0 N for 2.0 s D) applying a net force of 10.0 N for 0.5 s 34. In the diagram below, a 60.-kilogram rollerskater exerts a 10.-newton force on a 30.-kilogram rollerskater for 0.20 second. What is the magnitude of the impulse applied to the 30.-kilogram rollerskater? A) 50. N s B) 2.0 N s C) 6.0 N s D) 12 N s 35. When a 1.0-kilogram cart moving with a speed of 0.50 meter per second on a horizontal surface collides with a second 1.0-kilogram cart initially at rest, the carts lock together. What is the speed of the combined carts after the collision? [Neglect friction.] A) 1.0 m/s B) 0.50 m/s C) 0.25 m/s D) 0 m/s 36. A 3.1 kilogram gun initially at rest is free to move. When a kilogram bullet leaves the gun with a speed of 500. meters per second, what is the speed of the gun? A) 0.0 m/s B) 2.4 m/s C) 7.5 m/s D) 500. m/s 37. A 2.0-kilogram ball traveling north at 4.0 meters per second collides head on with a 1.0-kilogram ball traveling south at 8.0 meters per second. What is the magnitude of the total momentum of the two balls after collision? A) 0 kg-m/s B) 8.0 kg-m/s C) 16 kg-m/s D) 32 kg-m/s 38. An 80.-kilogram skater and a 60.-kilogram skater stand at rest in the center of a skating rink. The two skaters push each other apart. The 60.-kilogram skater moves with a velocity of 10. meters per second east. What is the velocity of the 80.-kilogram skater? [Neglect any frictional effects.] A) 0.13 m/s west B) 7.5 m/s west C) 10. m/s east D) 13. m/s east

5 39. Which object has the greatest inertia? A) a kg bullet traveling at 90. m/s B) a 30.-kg child traveling at 10. m/s on her bike C) a 490-kg elephant walking with a speed of 1.0 m/s D) a 1500-kg car at rest in a parking lot 40. A person is standing on a bathroom scale in an elevator car. If the scale reads a value greater than the weight of the person at rest, the elevator car could be moving A) downward at constant speed B) upward at constant speed C) downward at increasing speed D) upward at increasing speed 41. The diagram below shows a horizontal 12-newton force being applied to two blocks, A and B, initially at rest on a horizontal, frictionless surface. Block A has a mass of 1.0 kilogram and block B has a mass of 2.0 kilograms. The magnitude of the acceleration of block B is A) 6.0 m/s 2 B) 2.0 m/s 2 C) 3.0 m/s 2 D) 4.0 m/s Two forces, F1 and F2, are applied to a block on a frictionless, horizontal surface as shown below. If the magnitude of the block's acceleration is 2.0 meters per second 2, what is the mass of the block? A) 1 kg B) 5 kg C) 6 kg D) 7 kg 43. A 25-newton horizontal force northward and a 35-newton horizontal force southward act concurrently on a 15-kilogram object on a frictionless surface. What is the magnitude of the object's acceleration? A) 0.67 m/s 2 B) 1.7 m/s 2 C) 2.3 m/s 2 D) 4.0 m/s The graph below represents the relationship between the forces applied to an object and the corresponding accelerations produced. What is the inertial mass of the object? A) 1.0 kg B) 2.0 kg C) 0.50 kg D) 1.5 kg 45. What is the magnitude of the net force acting on a kilogram car as it accelerates from rest to a speed of 15 meters per second in 5.0 seconds? A) N B) N C) N D) N 46. A 400-newton girl standing on a dock exerts a force of 100 newtons on a newton sailboat as she pushes it away from the dock. How much force does the sailboat exert on the girl? A) 25 N B) 100 N C) 400 N D) N 47. An object weighing 4 Newtons rests on a horizontal tabletop. The force of the tabletop on the object is A) 0 N B) 4 N horizontally C) 4 N downward D) 4 N upward 48. On the planet Gamma, a 4.0-kilogram mass experiences a gravitational force of 24 Newtons. What is the acceleration due to gravity on planet Gamma? A) 0.17 m/s 2 B) 6.0 m/s 2 C) 9.8 m/s 2 D) 96 m/s What is the weight of a 5.0-kilogram object at the surface of the Earth? A) 5.0 kg B) 25 N C) 49 N D) 49 kg

6 50. The graph below shows the weight of three objects on planet X as a function of their mass. The acceleration due to gravity on planet X is A) 0.17 m/s 2 B) 6.0 m/s 2 C) 9.8 m/s 2 D) 50. m/s An 8.0-newton wooden block slides across a horizontal wooden floor at constant velocity. What is the magnitude of the force of kinetic friction between the block and the floor? A) 2.4 N B) 3.4 N C) 8.0 N D) 27 N 52. The diagram below shows a 4.0-kilogram object accelerating at 10. meters per second 2 on a rough horizontal surface. 54. If a 30-Newton force is required to accelerate a 2-kilogram object at 10 meters per second 2, over a level floor, then the magnitude of the frictional force acting on the object is A) 0 N B) 10 N C) 20 N D) 30 N 55. According to your reference table, Approximate Coefficents of Friction, what is the minimum horizontal force needed to start a 300. N steel block on a steel table in motion? A) 0.57 N B) 074 N C) 171 N D) 222 N 56. Jill is pulling a 200. Newton sled through the snow at constant velocity using a horizontal force of 10. Newtons. What is the kinetic coefficient of friction of the sled on the snow? A) 0.02 B) 0.05 C) 0.20 D) Two forces act concurrently on an object. Their resultant force has the largest magnitude when the angle between the forces is A) 0 B) 30 C) 90 D) In the diagram below, a 20.-newton force due north and a 20.-newton force due east act concurrently on an object, as shown in the diagram below. What is the magnitude of the frictional force Ff acting on the object? A) 5.0 N B) 10. N C) 20. N D) 40. N 53. The diagram below shows a student applying a 10.-newton force to slide a piece of wood at constant speed across a horizontal surface. After the wood is cut in half, one piece is placed on top of the other, as shown. What is the magnitude of the force, F, required to slide the stacked wood at constant speed across the surface? A) 40 N B) 20 N C) 10 N D) 5.0 N The additional force necessary to bring the object into a state of equilibrium is A) 20. N, northeast B) 20. N, southwest C) 28 N, northeast D) 28 N, southwest 59. A 5.0-newton force and a 7.0-newton force act concurrently on a point. As the angle between the forces is increased from 0 to 180, the magnitude of the resultant of the two forces changes from A) 0.0 N to 12.0 N B) 2.0 N to 12.0 N C) 12.0 N to 2.0 N D) 12.0 N to 0.0 N

7 60. A girl leaves a history classroom and walks 10. meters north to a drinking fountain. Then she turns and walks 30. meters south to an art classroom. What is the girl s total displacement from the history classroom to the art classroom? A) 20. m south B) 20. m north C) 40. m south D) 40. m north 61. The components of a 15-meters-per-second velocity at an angle of 60. above the horizontal are A) 7.5 m/s vertical and 13 m/s horizontal B) 13 m/s vertical and 7.5 m/s horizontal C) 6.0 m/s vertical and 9.0 m/s horizontal D) 9.0 m/s vertical and 6.0 m/s horizontal 62. An airplane flies with a velocity of 750. kilometers per hour, 30.0º south of east. What is the magnitude of the eastward component of the plane s velocity? A) 866 km/h B) 650 km/h C) 433 km/h D) 375km/h 63. Equilibrium exists in a system where three forces are acting concurrently on an object. If the system includes a 5.0-newton force due north and a 2.0-newton force due south, the third force must be A) 7.0 N south B) 7.0 N north C) 3.0 N south D) 3.0 N north 64. In the diagram below, the weight of a box on a plane inclined at 30. is represented by the vector W. 67. Which quantity includes both magnitude and direction? A) mass B) time C) distance D) velocity 68. A 75-kilogram bicyclist coasts down a hill at a constant speed of 12 meters per second. What is the kinetic energy of the bicyclist? A) J B) J C) J D) 1.1 l0 4 J 69. An object falls freely near Earth s surface. Which graph best represents the relationship between the object s kinetic energy and its time of fall A) B) C) D) 70. An object moving at a constant speed of 25 meters per second possesses 450 joules of kinetic energy. What is the object s mass? A) 0.72 kg B) 1.4 kg C) 18 kg D) 36 kg 71. A car travels at constant speed v up a hill from point A to point B, as shown in the diagram below. What is the magnitude of the component of the weight (W) that acts parallel to the incline? A) W B) 0.50 W C) 0.87 W D) 1.5 W 65. Which quantity is scalar? A) mass B) force C) momentum D) acceleration 66. Which terms represent a vector quantity and its respective unit? A) weight kilogram B) mass kilogram C) force newton D) momentum newton As the car travels from A to B, its gravitational potential energy A) increases and its kinetic energy decreases B) increases and its kinetic energy remains the same C) remains the same and its kinetic energy decreases D) remains the same and its kinetic energy remains the same

8 72. A 1.00-kilogram ball is dropped from the top of a building. Just before striking the ground, the ball s speed is 12.0 meters per second. What was the ball s gravitational potential energy, relative to the ground, at the instant it was dropped? [Neglect friction.] A) 6.00 J B) 24.0 J C) 72.0 J D) 144 J 73. A girl rides an escalator that moves her upward at constant speed. As the girl rises, how do her gravitational potential energy and kinetic energy change? A) Gravitational potential energy decreases and kinetic energy decreases. B) Gravitational potential energy decreases and kinetic energy remains the same. C) Gravitational potential energy increases and kinetic energy decreases. D) Gravitational potential energy increases and kinetic energy remains the same. 74. A spring gains 2.34 joules of elastic potential energy as it is compressed meter from its equilibrium position. What is the spring constant of this spring? A) 9.36 N/m B) 18.7 N/m C) 37.4 N/m D) 74.9 N/m 75. A spring with a spring constant of 4.0 newtons per meter is compressed by a force of 1.2 newtons. What is the total elastic potential energy stored in this compressed spring? A) 0.18 J B) 0.36 J C) 0.60 J D) 4.8 J 76. The graph below represents the relationship between the force applied to a spring and spring elongation for four different springs. Which spring has the greatest spring constant? A) A B) B C) C D) D 77. How much work is done by the force lifting a 0.1-kilogram hamburger vertically upward at constant velocity 0.3 meter from a table? A) 0.03 J B) 0.1 J C) 0.3 J D) 0.4 J 78. As a box is pushed 30. meters across a horizontal floor by a constant horizontal force of 25 newtons, the kinetic energy of the box increases by 300. joules. How much total internal energy is produced during this process? A) 150 J B) 250 J C) 450 J D) 750 J 79. As shown in the diagram below, a child applies a constant 20.-newton force along the handle of a wagon which makes a 25 angle with the horizontal. How much work does the child do in moving the wagon a horizontal distance of 4.0 meters? A) 5.0 J B) 34 J C) 73 J D) 80. J 80. A cart weighing 20 Newtons is pushed 10 meters on a level surface by a force of 5 Newtons. How much work was done on the cart? A) 15 J B) 50 J C) 100 J D) 200 J 81. A horizontal force of 40 Newtons pushes a block along a level table at a constant speed of 2 meters per second. How much work is done on the block in 6 seconds? A) 80 J B) 120 J C) 240 J D) 480 J 82. A 2.0-kilogram block sliding down a ramp from a height of 3.0 meters above the ground reaches the ground with a kinetic energy of 50. joules. The total work done by friction on the block as it slides down the ramp is approximately A) 6 J B) 9 J C) 18 J D) 44 J 83. When a force moves an object over a rough, horizontal surface at a constant velocity, the work done against friction produces an increase in the object s A) weight B) momentum C) potential energy D) internal energy

9 84. A block weighing 15 Newtons is pulled to the top of an incline that is 0.20 meter above the ground, as shown below. If 4.0 joules of work are needed to pull the block the full length of the incline, how much work is done against friction? A) 1.0 J B) 0.0 J C) 3.0 J D) 7.0 J 85. In the diagram below, 400. joules of work is done raising a 72-newton weight a vertical distance of 5.0 meters. 88. A 40.-kilogram student runs up a staircase to a floor that is 5.0 meters higher than her starting point in 7.0 seconds. The student s power output is A) 29 W B) 280 W C) W D) W 89. In raising an object vertically at a constant speed of 2.0 meters per second, 10. watts of power is developed. The weight of the object is A) 5.0 N B) 20. N C) 40. N D) 50. N 90. A motor used 120. watts of power to raise a 15-newton object in 5.0 seconds. Through what vertical distance was the object raised? A) 1.6 m B) 8.0 m C) 40. m D) 360 m 91. A 15.0-kilogram mass is moving at 7.50 meters per second on a horizontal, frictionless surface. What is the total work that must be done on the mass to increase its speed to 11.5 meters per second? A) 120. J B) 422 J C) 570. J D) 992 J 92. A horizontal force of 5.0 newtons acts on a 3.0-kilogram mass over a distance of 6.0 meters along a horizontal, frictionless surface. What is the change in kinetic energy of the mass during its movement over the 6.0-meter distance? A) 6.0 J B) 15 J C) 30. J D) 90. J 93. In the diagram below, an average force of 20. Newtons is used to pull back the string of a bow 0.60 meter. How much work is done to overcome friction as the weight is raised? A) 40. J B) 360 J C) 400. J D) 760 J 86. Which quantity is a measure of the rate at which work is done? A) energy B) power C) momentum D) velocity 87. The rate at which work is done is measured in A) Newtons B) joules C) calories D) watts As the arrow, leaves the bow, its kinetic energy is A) 3.4 J B) 6.0 J C) 12 J D) 33 J

10 96. A block weighing 40. newtons is released from rest on an incline 8.0 meters above the horizontal, as shown in the diagram below. 94. As the pendulum swings from position A to position B as shown in the diagram above, what is the relationship of kinetic energy to potential energy? [Neglect friction.] A) The kinetic energy decrease is more than the potential energy increase. B) The kinetic energy increase is more than the potential energy decrease. C) The kinetic energy decrease is equal to the potential energy increase. D) The kinetic energy increase is equal to the potential energy decrease. 95. A pendulum is made from a 7.50-kilogram mass attached to a rope connected to the ceiling of a gymnasium. The mass is pushed to the side until it is at position A, 1.5 meters higher than its equilibrium position. After it is released from rest at position A, the pendulum moves freely back and forth between positions A and B, as shown in the diagram below. If 50. joules of heat is generated as the block slides down the incline, the maximum kinetic energy of the block at the bottom of the incline is A) 50. J B) 270 J C) 320 J D) 3100 J 97. A ball is thrown vertically upward. As the ball rises, its total energy (neglecting friction) A) decreases B) increases C) remains the same What is the total amount of kinetic energy that the mass has as it swings freely through its equilibrium position? [Neglect friction.] A) 11 J B) 94 J C) 110 J D) 920 J

11 Base your answers to questions 98 through 100 on the information below. A roller coaster car has a mass of 290. kilograms. Starting from rest, the car acquires joules of kinetic energy as it descends to the bottom of a hill in 5.3 seconds. 98. Calculate the height of the hill. [Neglect friction.] [Show all work, including the equation and substitution with units.] 99. Calculate the speed of the roller coaster car at the bottom of the hill. [Show all work, including the equation and substitution with units.] 100. Calculate the magnitude of the average acceleration of the roller coaster car as it descends to the bottom of the hill. [Show all work, including the equation and substitution with units.] Base your answers to questions 101 and 102 on the information below. A 65-kilogram pole vaulter wishes to vault to a height of 5.5 meters Calculate the minimum amount of kinetic energy the vaulter needs to reach this height if air friction is neglected and all the vaulting energy is derived from kinetic energy. [Show all work, including the equation and substitution with units.] 102. Calculate the speed the vaulter must attain to have the necessary kinetic energy. [Show all work, including the equation and substitution with units.] Base your answers to questions 103 through 106 on the information below and on your knowledge of physics. The diagram below represents a 4.0-newton force applied to a kilogram copper block sliding to the right on a horizontal steel table Determine the weight of the block Calculate the magnitude of the force of friction acting on the moving block. [Show all work, including the equation and substitution with units.]

12 105. Determine the magnitude of the net force acting on the moving block Describe what happens to the magnitude of the velocity of the block as the block slides across the table The coefficient of kinetic friction between a 780.-newton crate and a level warehouse floor is Calculate the magnitude of the horizontal force required to move the crate across the floor at constant speed.

13 Answer Key midterm review 1. C 37. A 73. D C 38. B 74. D 3. C 39. D 75. A 4. A 40. D 76. A 5. D 6. C 7. B 8. C 9. D 10. C 11. B 12. C 13. D 14. C 15. A 16. C 41. D 42. B 43. A 44. C 45. A 46. B 47. D 48. B 49. C 50. B 51. A 52. B 77. C 78. C 79. C 80. B 81. D 82. B 83. D 84. A 85. A 86. B 87. D 88. B J m/s N or 2.0 N or 1.9 N N 106. The magnitude of the velocity increases. The block speeds up 107. Ff = ƒfn= (.200) (780. N) = 156 N 17. D 53. C 89. A 18. B 54. B 90. C 19. A 55. D 91. C 20. C 56. B 92. C 21. B 57. A 93. C 22. D 58. D 94. D 23. C 59. C 95. C 24. A 60. A 96. B 25. C 61. B 97. C 26. B 62. B A 63. C 28. D 64. B 29. A 65. A 30. B 31. B 66. C 67. D C 68. C 33. C 69. D 34. B 70. B 35. C 71. B 36. B 72. C