3. The motion does not change

5. The greater the mass, the greater the force necessary

7. Ice

9. Friction

11. The force increases with the increased mass.

13. Mass and Distance

15. 2J Work = Force x Distance

17. Make work easier

19. Ax

21. Mechanical Advantage = Force out divided by Force in

22. Mechanical Advantage = Force out divided by Force in. 9N divided by 3N = 3

24. A. Reduce the amount of work that Is done.

26. 2

28. The chair pushes on the baby

29. A. Input force is 40N and work done is 0J. B. Input force is 40N and work done is 600J. C. Output force is 40N and work done is 150J. D. D. Output force is 150N and work is 40J.

30. A. Input force is 40N and work done is 0J. B. Input force is 40N and work done is 600J. C. Output force is 40N and work done is 150J. D. D. Output force is 150N and work is 40J. A. Input force is 40N and work done is 0J.

32. Inertia

34. Acceleration

36. 0.5 m/s

38. Because the child is constantly changing direction!

39. A. Gravity causes a net downward force on the block B. B. Gravitational attraction decreases as the block gets closer to the ground. C. C. Gravitational attraction causes the block to accelerate as it falls. D. D. Gravity causes an unbalanced force on the block.

40. A. Gravity causes a net downward force on the block B. B. Gravitational attraction decreases as the block gets closer to the ground. C. C. Gravitational attraction causes the block to accelerate as it falls. D. D. Gravity causes an unbalanced force on the block. B.

42. ½ x5 kg x (2 m/s) 2 =1/2 x 5kg x 4m/s =1/2 x 20J =10J

44. Position

46. Motion

48. A force

50. Contact

52. Reference Point

54. Gravity

56. Friction

58. Relative Motion

60. Net force

62. Speed is distance divided by time

63. A. Increase force B. Decrease force C. Increase mass D. Increase inertia

64. A. Increase force B. Decrease force C. Increase mass D. Increase inertia A. Increase force

66. Reference point

68. Speed = distance divided by time 4 km/h Change the “half an hour” to 0.5 hours.

70. Size and direction

72. Newton

73. a. Zero b. The original momentum of the more massive marble c. The original momentum of the smaller marble d. Twice the momentum of the more massive marble

74. a. Zero b. The original momentum of the more massive marble c. The original momentum of the smaller marble d. Twice the momentum of the more massive marble B.

76. A = final velocity – initial velocity divided by 2. 10 m/s/s

78. The box moves toward John

79. Large rock, pencil feather, book

80. Feather, pencil, book, large rock.

81. a. No acceleration b. Positive acceleration c. Negative acceleration d. Constant velocity

82. a. No acceleration b. Positive acceleration c. Negative acceleration d. Constant velocity C.

84. pressure

86. Pressure = force divided by area

88. pascal

90. True

92. Increasing elevation decreases air pressure Increasing depth increases water pressure

94. friction

95. a. Force and speed b. Force and distance c. Energy and time d. Energy and distance

96. a. Force and speed b. Force and distance c. Energy and time d. Energy and distance B

98. No. Work requires movement in the direction of the force

99. a. Force b. Work c. Energy d. power

100. a. Force b. Work c. Energy d. Power D

102. Horsepower

104. They add together

105. a. Increase mass b. Decrease mass c. Decrease force d. Increase both mass and force proportionally

106. a. Increase mass b. Decrease mass c. Decrease force d. Increase both mass and force proportionally B

107. A. Your shoes on the sidewalk while walking. B. Bike tires on the road as you ride C. Ice skates while skating D. Lighting a match

108. A. Your shoes on the sidewalk while walking. B. Bike tires on the road as you ride C. Ice skates while skating D. Lighting a match B