NAME MIDTERM REVIEW

A) 0.39 m/s B) 1.2 m/sC) 2.5 m/s D) 4.3 m/s

1. A student on an amusement park ride moves in a circularpath with a radius of 3.5 meters once every 8.9 seconds.The student moves at an average speed of

A) 20. m B) 20. m/sC) 20. m east D) 20. m/s east

2. A car travels 20. meters east in 1.0 second. Thedisplacement of the car at the end of this 1.0-secondinterval is

A) velocity B) accelerationC) position D) direction

3. A moving body must undergo a change of

A) 2.5 m/s B) 5.0 m/sC) 6.5 m/s D) 7.0 m/s

4. A car travels 90. meters due north in 15 seconds. Thenthe car turns around and travels 40. meters due south in5.0 seconds. What is the magnitude of the averagevelocity of the car during this 20.-second interval?

A) 12 m B) 58 m C) 70. m D) 83 m

5. A truck, initially traveling at a speed of 22 meters persecond, increases speed at a constant rate of 2.4 metersper second 2 for 3.2 seconds. What is the total distancetraveled by the truck during this 3.2-second timeinterval?

A) 1.0 m B) 2.0 m C) 16 m D) 32 m

6. A roller coaster, traveling with an initial speed of 15meters per second, decelerates uniformly at –7.0 metersper second2 to a full stop. Approximately how far doesthe roller coaster travel during its deceleration?

A) 5 m/sec B) 5 m/sec2

C) 10 m/sec D) 10 m/sec2

7. Starting from rest, an object rolls freely down an inclinethat is 10 meters long in 2 seconds. The acceleration ofthe object is approximately

A) 12 m/s B) 27 m/sC) 3.0 m/s D) 7.0 m/s

8. A child riding a bicycle at 15 meters per secondaccelerates at -3.0 meters per second2 for 4.0 seconds.What is the child’s speed at the end of this 4.0-secondinterval?

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.

9. A rock is dropped from a bridge. What happens to themagnitude of the acceleration and the speed of the rockas it falls? [Neglect friction.]

A) 5 m/s B) 2 m/sC) 50 m/s D) 125 m/s

10. A rock dropped off a bridge takes 5 seconds to hit thewater. Approximately what was the rock's velocity justbefore impact?

A) 0.50 m/s B) 7.4 m/sC) 9.8 m/s D) 15 m/s

11. A ball is thrown straight downward with a speed of0.50 meter per second from a height of 4.0 meters.What is the speed of the ball 0.70 second after it isreleased? [Neglect friction.]

A) 1.1 m/s2 B) 2.3 m/s2

C) 3.6 m/s2 D) 9.8 m/s2

12. A rock falls from rest a vertical distance of 0.72 meterto the surface of a planet in 0.63 second. The magnitudeof the acceleration due to gravity on the planet is

A) 0 m B) 8 m C) 16 m D) 24 m

13. The graph below represents the displacement of anobject moving in a straight line as a function of time.

What was the total distance traveled by the objectduring the 10.0-second time interval?

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A) B)

C) D)

14. Which graph best represents the motion of an objectwhose speed is increasing?

15. Base your answer to the following question on the graph below, which represents the relationship betweenthe displacement of an object and its time of travel along a straight line.

A) 0 m B) 2 m C) 8 m D) 16 m

What is the magnitude of the object's total displacement after 8.0 seconds?

Base your answers to questions 16 through 20 on the graph below which represents the displacement of anobject as a function of time.

A) 0 m B) 2.0 m C) 3.0 m D) 9.0 m

16. How far is the object from the starting point at the end of 3 seconds?

A) 1.0 m/s B) 2.0 m/s C) 3.0 m/s D) 1.5 m/s

17. What is the velocity of the object at t = 1 second?

A) 0-2 s B) 2-3 s C) 3-4 s D) 4-6 s

18. During which time interval is the object at rest?

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A) 1.0 m/s B) 2.0 m/s C) 3.0 m/s D) 0 m/s

19. What is the average velocity of the object from t = 0 to t = 3 seconds?

A) 0-2 s B) 2-3 s C) 3-4 s D) 4-6 s

20. During which time interval is the object accelerating?

Base your answers to questions 21 through 26 on the graph below which represents the relationshipbetween speed and time for an object in motion along a straight line.

A) 5.0 m/sec2 B) 7.5 m/sec2 C) 12.5 m/sec2 D) 17.5 m/sec2

21. What is the acceleration of the object during the time interval t = 3 seconds to t = 5 seconds?

A) 7.5 m/sec B) 10 m/sec C) 15 m/sec D) 17.5 m/sec

22. What is the average speed of the object during the time interval t = 6 seconds to t = 8 seconds'?

A) 15 m B) 20 m C) 25 m D) 30 m

23. What is the total distance traveled by the object during the first 3 seconds?

A) AB B) CD C) DE D) EF

24. During which interval is the object's acceleration the greatest?

A) zero B) increasingC) decreasing D) constant, but not zero

25. During the interval t = 8 seconds to t = 10 seconds, the speed of the object is

A) 10 m/sec B) 25 m/sec C) 150 m/sec D) 250 m/sec

26. What is the maximum speed reached by the object during the 10 seconds of travel?

A) 4.5 × 104 kg•m/s, eastB) 4.5 × 104 kg•m/s, westC) 4.5 × 106 kg•m, eastD) 4.5 × 106 kg•m, west

27. What is the momentum of a 1.5 × 103-kilogram car as ittravels at 30. meters per second due east for 60.seconds?

A) 64 kg B) 20 kgC) 12 kg D) 4.0 kg

28. An object traveling at 4.0 meters per second has amomentum of 16 kilogram-meters per second. What isthe mass of the object?

MIDTERM REVIEW

A) increasing the length of time the force acts onthe driver

B) decreasing the distance over which the force actson the driver

C) increasing the rate of acceleration of the driverD) decreasing the mass of the driver

29. An air bag is used to safely decrease the momentum ofa driver in a car accident. The air bag reduces themagnitude of the force acting on the driver by

A) 5.0 kg•m/s B) 15 kg•m/sC) 3.0 kg•m/s D) 45 kg•m/s

30. A 3.0-kilogram object is acted upon by an impulsehaving a magnitude of 15 newton•seconds. What is themagnitude of the object’s change in momentum due tothis impulse?

A) energy B) impulseC) power D) work

31. Which quantity has both a magnitude and a direction?

A) 120 N B) 290 N C) 690 N D) 920 N

32. A 75-kilogram hockey player is skating across the ice ata speed of 6.0 meters per second. What is themagnitude of the average force required to stop theplayer in 0.65 second?

A) accelerating it from rest to 3.0 m/sB) accelerating it from 2.0 m/s to 4.0 m/sC) applying a net force of 5.0 N for 2.0 sD) applying a net force of 10.0 N for 0.5 s

33. Which situation will produce the greatest change ofmomentum for a 1.0-kilogram cart?

A) 50. N•s B) 2.0 N•sC) 6.0 N•s D) 12 N•s

34. In the diagram below, a 60.-kilogram rollerskater exertsa 10.-newton force on a 30.-kilogram rollerskater for0.20 second.

What is the magnitude of the impulse applied to the30.-kilogram rollerskater?

A) 1.0 m/s B) 0.50 m/sC) 0.25 m/s D) 0 m/s

35. When a 1.0-kilogram cart moving with a speed of 0.50meter per second on a horizontal surface collides with asecond 1.0-kilogram cart initially at rest, the carts locktogether. What is the speed of the combined carts afterthe collision? [Neglect friction.]

A) 0.0 m/s B) 2.4 m/sC) 7.5 m/s D) 500. m/s

36. A 3.1 kilogram gun initially at rest is free to move.When a 0.015-kilogram bullet leaves the gun with aspeed of 500. meters per second, what is the speed ofthe gun?

A) 0 kg-m/s B) 8.0 kg-m/sC) 16 kg-m/s D) 32 kg-m/s

37. A 2.0-kilogram ball traveling north at 4.0 meters persecond collides head on with a 1.0-kilogram balltraveling south at 8.0 meters per second. What is themagnitude of the total momentum of the two balls aftercollision?

A) 0.13 m/s west B) 7.5 m/s westC) 10. m/s east D) 13. m/s east

38. An 80.-kilogram skater and a 60.-kilogram skater standat rest in the center of a skating rink. The two skaterspush each other apart. The 60.-kilogram skater moveswith a velocity of 10. meters per second east. What isthe velocity of the 80.-kilogram skater? [Neglect anyfrictional effects.]

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A) a 0.010-kg bullet traveling at 90. m/sB) a 30.-kg child traveling at 10. m/s on her bikeC) a 490-kg elephant walking with a speed of 1.0 m/sD) a 1500-kg car at rest in a parking lot

39. Which object has the greatest inertia?

A) downward at constant speedB) upward at constant speedC) downward at increasing speedD) upward at increasing speed

40. A person is standing on a bathroom scale in an elevatorcar. If the scale reads a value greater than the weight ofthe person at rest, the elevator car could be moving

A) 6.0 m/s2 B) 2.0 m/s2

C) 3.0 m/s2 D) 4.0 m/s2

41. The diagram below shows a horizontal 12-newton forcebeing applied to two blocks, A and B, initially at rest ona horizontal, frictionless surface. Block A has a mass of1.0 kilogram and block B has a mass of 2.0 kilograms.

The magnitude of the acceleration of block B is

A) 1 kg B) 5 kg C) 6 kg D) 7 kg

42. Two forces, F1 and F2, are applied to a block on africtionless, horizontal surface as shown below.

If the magnitude of the block's acceleration is 2.0meters per second2, what is the mass of the block?

A) 0.67 m/s2 B) 1.7 m/s2

C) 2.3 m/s2 D) 4.0 m/s2

43. A 25-newton horizontal force northward and a35-newton horizontal force southward act concurrentlyon a 15-kilogram object on a frictionless surface. Whatis the magnitude of the object's acceleration?

A) 1.0 kg B) 2.0 kgC) 0.50 kg D) 1.5 kg

44. The graph below represents the relationship betweenthe forces applied to an object and the correspondingaccelerations produced.

What is the inertial mass of the object?

A) 6.0 × 103 N B) 2.0 × 104 NC) 3.0 × 104 N D) 6.0 × 104 N

45. What is the magnitude of the net force acting on a 2.0 × 103- kilogram car as it accelerates from rest to aspeed of 15 meters per second in 5.0 seconds?

A) 25 N B) 100 NC) 400 N D) 10 000 N

46. A 400-newton girl standing on a dock exerts a force of100 newtons on a 10 000-newton sailboat as she pushesit away from the dock. How much force does thesailboat exert on the girl?

A) 0 N B) 4 N horizontallyC) 4 N downward D) 4 N upward

47. An object weighing 4 Newtons rests on a horizontaltabletop. The force of the tabletop on the object is

A) 0.17 m/s2 B) 6.0 m/s2

C) 9.8 m/s2 D) 96 m/s2

48. On the planet Gamma, a 4.0-kilogram mass experiencesa gravitational force of 24 Newtons. What is theacceleration due to gravity on planet Gamma?

A) 5.0 kg B) 25 NC) 49 N D) 49 kg

49. What is the weight of a 5.0-kilogram object at thesurface of the Earth?

MIDTERM REVIEW

A) 0.17 m/s2 B) 6.0 m/s2

C) 9.8 m/s2 D) 50. m/s2

50. The graph below shows the weight of three objects onplanet X as a function of their mass.

The acceleration due to gravity on planet X is

A) 2.4 N B) 3.4 N C) 8.0 N D) 27 N

51. An 8.0-newton wooden block slides across a horizontalwooden floor at constant velocity. What is themagnitude of the force of kinetic friction between theblock and the floor?

A) 5.0 N B) 10. N C) 20. N D) 40. N

52. The diagram below shows a 4.0-kilogram objectaccelerating at 10. meters per second2 on a roughhorizontal surface.

What is the magnitude of the frictional force Ff actingon the object?

A) 40 N B) 20 N C) 10 N D) 5.0 N

53. The diagram below shows a student applying a10.-newton force to slide a piece of wood at constantspeed across a horizontal surface. After the wood is cutin half, one piece is placed on top of the other, asshown.

What is the magnitude of the force, F, required to slidethe stacked wood at constant speed across the surface?

A) 0 N B) 10 N C) 20 N D) 30 N

54. If a 30-Newton force is required to accelerate a2-kilogram object at 10 meters per second2, over a levelfloor, then the magnitude of the frictional force actingon the object is

A) 0.57 N B) 074 NC) 171 N D) 222 N

55. According to your reference table, ApproximateCoefficents of Friction, what is the minimum horizontalforce needed to start a 300. N steel block on a steeltable in motion?

A) 0.02 B) 0.05 C) 0.20 D) 20

56. Jill is pulling a 200. Newton sled through the snow atconstant velocity using a horizontal force of 10.Newtons. What is the kinetic coefficient of friction ofthe sled on the snow?

A) 0° B) 30° C) 90° D) 180°

57. Two forces act concurrently on an object. Theirresultant force has the largest magnitude when theangle between the forces is

A) 20. N, northeast B) 20. N, southwestC) 28 N, northeast D) 28 N, southwest

58. In the diagram below, a 20.-newton force due north anda 20.-newton force due east act concurrently on anobject, as shown in the diagram below.

The additional force necessary to bring the object into astate of equilibrium is

A) 0.0 N to 12.0 N B) 2.0 N to 12.0 NC) 12.0 N to 2.0 N D) 12.0 N to 0.0 N

59. A 5.0-newton force and a 7.0-newton force actconcurrently on a point. As the angle between theforces is increased from 0° to 180°, the magnitude ofthe resultant of the two forces changes from

MIDTERM REVIEW

A) 20. m south B) 20. m northC) 40. m south D) 40. m north

60. A girl leaves a history classroom and walks 10. metersnorth to a drinking fountain. Then she turns and walks30. meters south to an art classroom. What is the girl’stotal displacement from the history classroom to the artclassroom?

A) 7.5 m/s vertical and 13 m/s horizontalB) 13 m/s vertical and 7.5 m/s horizontalC) 6.0 m/s vertical and 9.0 m/s horizontalD) 9.0 m/s vertical and 6.0 m/s horizontal

61. The components of a 15-meters-per-second velocity atan angle of 60.° above the horizontal are

A) 866 km/h B) 650 km/hC) 433 km/h D) 375km/h

62. An airplane flies with a velocity of 750. kilometers perhour, 30.0º south of east. What is the magnitude of theeastward component of the plane’s velocity?

A) 7.0 N south B) 7.0 N northC) 3.0 N south D) 3.0 N north

63. Equilibrium exists in a system where three forces areacting concurrently on an object. If the system includesa 5.0-newton force due north and a 2.0-newton forcedue south, the third force must be

A) W B) 0.50 WC) 0.87 W D) 1.5 W

64. In the diagram below, the weight of a box on a planeinclined at 30. is represented by the vector W.

What is the magnitude of the component of the weight(W) that acts parallel to the incline?

A) mass B) forceC) momentum D) acceleration

65. Which quantity is scalar?

A) weight – kilogramB) mass – kilogramC) force – newtonD) momentum – newton

66. Which terms represent a vector quantity and itsrespective unit?

A) mass B) timeC) distance D) velocity

67. Which quantity includes both magnitude and direction?

A) 4.5 102 J B) 9.0 102 JC) 5.4 103 J D) 1.1 l04 J

68. A 75-kilogram bicyclist coasts down a hill at a constantspeed of 12 meters per second. What is the kineticenergy of the bicyclist?

A) B)

C) D)

69. An object falls freely near Earth’s surface. Which graphbest represents the relationship between the object’skinetic energy and its time of fall

A) 0.72 kg B) 1.4 kgC) 18 kg D) 36 kg

70. An object moving at a constant speed of 25 meters persecond possesses 450 joules of kinetic energy. What isthe object’s mass?

A) increases and its kinetic energy decreasesB) increases and its kinetic energy remains the

sameC) remains the same and its kinetic energy decreasesD) remains the same and its kinetic energy remains

the same

71. A car travels at constant speed v up a hill from point A to point B, as shown in the diagram below.

As the car travels from A to B, its gravitational potentialenergy

MIDTERM REVIEW

A) 6.00 J B) 24.0 JC) 72.0 J D) 144 J

72. A 1.00-kilogram ball is dropped from the top of abuilding. Just before striking the ground, the ball’sspeed is 12.0 meters per second. What was the ball’sgravitational potential energy, relative to the ground, atthe instant it was dropped? [Neglect friction.]

A) Gravitational potential energy decreases andkinetic energy decreases.

B) Gravitational potential energy decreases andkinetic energy remains the same.

C) Gravitational potential energy increases andkinetic energy decreases.

D) Gravitational potential energy increases andkinetic energy remains the same.

73. A girl rides an escalator that moves her upward atconstant speed. As the girl rises, how do hergravitational potential energy and kinetic energychange?

A) 9.36 N/m B) 18.7 N/mC) 37.4 N/m D) 74.9 N/m

74. A spring gains 2.34 joules of elastic potential energy asit is compressed 0.250 meter from its equilibriumposition. What is the spring constant of this spring?

A) 0.18 J B) 0.36 JC) 0.60 J D) 4.8 J

75. A spring with a spring constant of 4.0 newtons permeter is compressed by a force of 1.2 newtons. What isthe total elastic potential energy stored in thiscompressed spring?

A) A B) B C) C D) D

76. The graph below represents the relationship betweenthe force applied to a spring and spring elongation forfour different springs.

Which spring has the greatest spring constant?

A) 0.03 J B) 0.1 J C) 0.3 J D) 0.4 J

77. How much work is done by the force lifting a0.1-kilogram hamburger vertically upward at constantvelocity 0.3 meter from a table?

A) 150 J B) 250 J C) 450 J D) 750 J

78. As a box is pushed 30. meters across a horizontal floorby a constant horizontal force of 25 newtons, thekinetic energy of the box increases by 300. joules. Howmuch total internal energy is produced during thisprocess?

A) 5.0 J B) 34 J C) 73 J D) 80. J

79. As shown in the diagram below, a child applies aconstant 20.-newton force along the handle of a wagonwhich makes a 25° angle with the horizontal.

How much work does the child do in moving thewagon a horizontal distance of 4.0 meters?

A) 15 J B) 50 J C) 100 J D) 200 J

80. A cart weighing 20 Newtons is pushed 10 meters on alevel surface by a force of 5 Newtons. How much workwas done on the cart?

A) 80 J B) 120 J C) 240 J D) 480 J

81. A horizontal force of 40 Newtons pushes a block alonga level table at a constant speed of 2 meters per second.How much work is done on the block in 6 seconds?

A) 6 J B) 9 J C) 18 J D) 44 J

82. A 2.0-kilogram block sliding down a ramp from aheight of 3.0 meters above the ground reaches theground with a kinetic energy of 50. joules. The totalwork done by friction on the block as it slides down theramp is approximately

A) weight B) momentumC) potential energy D) internal energy

83. When a force moves an object over a rough, horizontalsurface at a constant velocity, the work done againstfriction produces an increase in the object’s

MIDTERM REVIEW

A) 1.0 J B) 0.0 J C) 3.0 J D) 7.0 J

84. A block weighing 15 Newtons is pulled to the top of anincline that is 0.20 meter above the ground, as shownbelow.

If 4.0 joules of work are needed to pull the block thefull length of the incline, how much work is doneagainst friction?

A) 40. J B) 360 J C) 400. J D) 760 J

85. In the diagram below, 400. joules of work is doneraising a 72-newton weight a vertical distance of 5.0meters.

How much work is done to overcome friction as theweight is raised?

A) energy B) powerC) momentum D) velocity

86. Which quantity is a measure of the rate at which workis done?

A) Newtons B) joulesC) calories D) watts

87. The rate at which work is done is measured in

A) 29 W B) 280 WC) 1.4 × 103 W D) 1.4 × 104 W

88. A 40.-kilogram student runs up a staircase to a floorthat is 5.0 meters higher than her starting point in 7.0seconds. The student’s power output is

A) 5.0 N B) 20. N C) 40. N D) 50. N

89. In raising an object vertically at a constant speed of 2.0meters per second, 10. watts of power is developed.The weight of the object is

A) 1.6 m B) 8.0 mC) 40. m D) 360 m

90. A motor used 120. watts of power to raise a 15-newtonobject in 5.0 seconds. Through what vertical distancewas the object raised?

A) 120. J B) 422 JC) 570. J D) 992 J

91. A 15.0-kilogram mass is moving at 7.50 meters persecond on a horizontal, frictionless surface. What is thetotal work that must be done on the mass to increase itsspeed to 11.5 meters per second?

A) 6.0 J B) 15 J C) 30. J D) 90. J

92. A horizontal force of 5.0 newtons acts on a3.0-kilogram mass over a distance of 6.0 meters along ahorizontal, frictionless surface. What is the change inkinetic energy of the mass during its movement overthe 6.0-meter distance?

A) 3.4 J B) 6.0 J C) 12 J D) 33 J

93. In the diagram below, an average force of 20. Newtonsis used to pull back the string of a bow 0.60 meter.

As the arrow, leaves the bow, its kinetic energy is

MIDTERM REVIEW

A) The kinetic energy decrease is more than thepotential energy increase.

B) The kinetic energy increase is more than thepotential energy decrease.

C) The kinetic energy decrease is equal to thepotential energy increase.

D) The kinetic energy increase is equal to thepotential energy decrease.

94. As the pendulum swings fromposition A to position B as shown in the diagram above,what is the relationship of kinetic energy to potentialenergy? [Neglect friction.]

A) 11 J B) 94 J C) 110 J D) 920 J

95. A pendulum is made from a 7.50-kilogram massattached to a rope connected to the ceiling of agymnasium. The mass is pushed to the side until it is atposition A, 1.5 meters higher than its equilibriumposition. After it is released from rest at position A, thependulum moves freely back and forth betweenpositions A and B, as shown in the diagram below.

What is the total amount of kinetic energy that the masshas as it swings freely through its equilibrium position?[Neglect friction.]

A) 50. J B) 270 JC) 320 J D) 3100 J

96. A block weighing 40. newtons is released from rest onan incline 8.0 meters above the horizontal, as shown inthe diagram below.

If 50. joules of heat is generated as the block slidesdown the incline, the maximum kinetic energy of theblock at the bottom of the incline is

A) decreases B) increasesC) remains the same

97. A ball is thrown vertically upward. As the ball rises, itstotal energy (neglecting friction)

MIDTERM REVIEW

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 3.13 × 105

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 theequation and substitution with units.]

100. Calculate the magnitude of the average acceleration of the roller coaster car as it descends to the bottomof the hill. [Show all work, including the equation and substitution with units.]

Base your answers to questions 101 and 102 on theinformation below.

A 65-kilogram pole vaulter wishes to vault to aheight of 5.5 meters.

101. Calculate the minimum amount of kinetic energy thevaulter needs to reach this height if air friction isneglected and all the vaulting energy is derived fromkinetic energy. [Show all work, including the equationand substitution with units.]

102. Calculate the speed the vaulter must attain to have thenecessary kinetic energy. [Show all work, includingthe equation and substitution with units.]

Base your answers to questions 103 through 106 on the information below and on your knowledge ofphysics.

The diagram below represents a 4.0-newton force applied to a 0.200-kilogram copper blocksliding to the right on a horizontal steel table.

103. Determine the weight of the block.

104. Calculate the magnitude of the force of friction acting on the moving block. [Show all work, including theequation and substitution with units.]

MIDTERM REVIEW

105. Determine the magnitude of the net force acting on the moving block.

106. Describe what happens to the magnitude of the velocity of the block as the block slides acrossthe table.

107. The coefficient of kinetic friction between a780.-newton crate and a level warehouse floor is0.200. Calculate the magnitude of the horizontal forcerequired to move the crate across the floor at constantspeed.

Answer Keymidterm review

1. C2. C3. C4. A5. D6. C7. B8. C9. D10. C11. B12. C13. D14. C15. A16. C17. D18. B19. A20. C21. B22. D23. C24. A25. C26. B27. A28. D29. A30. B31. B32. C33. C34. B35. C36. B

37. A38. B39. D40. D41. D42. B43. A44. C45. A46. B47. D48. B49. C50. B51. A52. B53. C54. B55. D56. B57. A58. D59. C60. A61. B62. B63. C64. B65. A66. C67. D68. C69. D70. B71. B72. C

73. D74. D75. A76. A77. C78. C79. C80. B81. D82. B83. D84. A85. A86. B87. D88. B89. A90. C91. C92. C93. C94. D95. C96. B97. C98.

99.

100.

101. 3.5 × 103 J102. 10 m/s103. 1.96 N or 2.0 N or

1.9 N104.105. 3.3 N106. — The magnitude of

the velocity increases.— The block speedsup

107. Ff = ƒFn= (.200) (780.N) = 156 N