1. Chapter 2 Clickers Conceptual Integrated Science Second Edition © 2013 Pearson Education, Inc. Describing Motion

2. © 2013 Pearson Education, Inc. The force due to gravity on a body is the body's a)mass. b)weight. c)density. d)all of the above.

3. © 2013 Pearson Education, Inc. The force due to gravity on a body is the body's a)mass. b)weight. c)density. d)all of the above.

4. © 2013 Pearson Education, Inc. When the mass of an object is compared to its volume, the concept is a)mass. b)weight. c)volume. d)density.

5. © 2013 Pearson Education, Inc. When the mass of an object is compared to its volume, the concept is a)mass. b)weight. c)volume. d)density.

6. © 2013 Pearson Education, Inc. When we say that 1 kilogram weighs 10 N, we mean that a)1 kg is 10 N. b)it's true at Earth's surface. c)it's true everywhere. d)mass and weight are one and the same.

7. © 2013 Pearson Education, Inc. When we say that 1 kilogram weighs 10 N, we mean that a)1 kg is 10 N. b)it's true at Earth's surface. c)it's true everywhere. d)mass and weight are one and the same.

8. © 2013 Pearson Education, Inc. The mass of 1 kilogram of iron a)is less on the Moon. b)is the same on the Moon. c)is greater on the Moon. d)weighs the same everywhere.

9. © 2013 Pearson Education, Inc. The mass of 1 kilogram of iron a)is less on the Moon. b)is the same on the Moon. c)is greater on the Moon. d)weighs the same everywhere. Comment: But is the weight of 1 kg of iron the same on the Earth and the Moon?

10. © 2013 Pearson Education, Inc. The density of 5 kilograms of iron is a)less than the density of 10 kg of iron. b)the same as the density of 10 kg of iron. c)greater than the density of 10 kg of iron. d)none of the above.

11. © 2013 Pearson Education, Inc. The density of 5 kilograms of iron is a)less than the density of 10 kg of iron. b)the same as the density of 10 kg of iron. c)greater than the density of 10 kg of iron. d)none of the above. Explanation: Density = mass/volume. Twice the mass of iron has twice the volume. The density of any amount of iron is the same. The density of a substance is a property of the substance.

12. © 2013 Pearson Education, Inc. A pair of 3-N and 4-N forces CANNOT have a resultant of a)0 N. b)1 N. c)7 N. d)But it can have any of the above.

13. © 2013 Pearson Education, Inc. A pair of 3-N and 4-N forces CANNOT have a resultant of a)0 N. b)1 N. c)7 N. d)But it can have any of the above. Explanation: When parallel, the two vectors can add to 7 N or subtract to 1 N. They cannot cancel to zero.

14. © 2013 Pearson Education, Inc. A pair of parallel forces of 8 N and 12 N can have a resultant of a)4 N. b)20 N. c)both of the above. d)neither of the above.

15. © 2013 Pearson Education, Inc. A pair of parallel forces of 8 N and 12 N can have a resultant of a)4 N. b)20 N. c)both of the above. d)neither of the above. Explanation: When parallel, 12 N + 8 N = 20 N, or 12 N – 8 N = 4 N.

16. © 2013 Pearson Education, Inc. The equilibrium rule,  F = 0, applies to a)objects or systems at rest. b)objects or systems in uniform motion in a straight line. c)both of the above. d)none of the above.

17. © 2013 Pearson Education, Inc. The equilibrium rule,  F = 0, applies to a)objects or systems at rest. b)objects or systems in uniform motion in a straight line. c)both of the above. d)none of the above. Comment: We say objects moving in uniform motion in a straight line are not accelerating.

18. © 2013 Pearson Education, Inc. When you stand on two bathroom scales, with more weight on one scale than on the other, the readings on both scales will a)cancel to zero. b)add to equal your weight. c)add to be somewhat less than your weight. d)add to be somewhat more than your weight.

19. © 2013 Pearson Education, Inc. When you stand on two bathroom scales, with more weight on one scale than on the other, the readings on both scales will a)cancel to zero. b)add to equal your weight. c)add to be somewhat less than your weight. d)add to be somewhat more than your weight.

20. © 2013 Pearson Education, Inc. When Nellie Newton hangs evenly by a pair of vertical ropes, the tension in each rope will be a)less than half her weight. b)half her weight. c)more than half her weight. d)equal to her weight.

21. © 2013 Pearson Education, Inc. When Nellie Newton hangs evenly by a pair of vertical ropes, the tension in each rope will be a)less than half her weight. b)half her weight. c)more than half her weight. d)equal to her weight.

22. © 2013 Pearson Education, Inc. When an airplane flies horizontally at constant speed in a straight line, the air drag on the plane is a)less than the amount of thrust. b)equal to the amount of thrust. c)more than the amount of thrust. d)none of the above.

23. © 2013 Pearson Education, Inc. When an airplane flies horizontally at constant speed in a straight line, the air drag on the plane is a)less than the amount of thrust. b)equal to the amount of thrust. c)more than the amount of thrust. d)none of the above.

24. © 2013 Pearson Education, Inc. When an airplane flying horizontally in a straight line gains speed, the thrust on the plane is a)less than the amount of air drag. b)equal to the amount of air drag. c)more than the amount of air drag. d)none of the above.

25. © 2013 Pearson Education, Inc. When an airplane flying horizontally in a straight line gains speed, the thrust on the plane is a)less than the amount of air drag. b)equal to the amount of air drag. c)more than the amount of air drag. d)none of the above. Explanation: In gaining speed, the net force is greater than zero in the direction of the thrust, so thrust exceeds air drag. It is not in equilibrium.

26. © 2013 Pearson Education, Inc. The force of friction between materials sliding against each other depends on a)the kind of materials. b)the roughness of the materials. c)the force with which they are pressed together. d)all of the above.

27. © 2013 Pearson Education, Inc. The force of friction between materials sliding against each other depends on a)the kind of materials. b)the roughness of the materials. c)the force with which they are pressed together. d)all of the above.

28. © 2013 Pearson Education, Inc. The difference between speed and velocity mostly involves a)amount. b)direction. c)acceleration. d)all of the above.

29. © 2013 Pearson Education, Inc. The difference between speed and velocity mostly involves a)amount. b)direction. c)acceleration. d)all of the above.

30. © 2013 Pearson Education, Inc. The kind of speed you read on a speedometer is a)average speed. b)instantaneous speed. c)changing speed. d)constant speed.

31. © 2013 Pearson Education, Inc. The kind of speed you read on a speedometer is a)average speed. b)instantaneous speed. c)changing speed. d)constant speed.

32. © 2013 Pearson Education, Inc. Distance traveled is equal to average speed multiplied by a)distance. b)time. c)acceleration. d)instantaneous speed.

33. © 2013 Pearson Education, Inc. Distance traveled is equal to average speed multiplied by a)distance. b)time. c)acceleration. d)instantaneous speed.

34. © 2013 Pearson Education, Inc. Constant speed in a constant direction is a)constant velocity. b)acceleration. c)both of the above. d)neither of the above.

35. © 2013 Pearson Education, Inc. Constant speed in a constant direction is a)constant velocity. b)acceleration. c)both of the above. d)neither of the above.

36. © 2013 Pearson Education, Inc. When a car rounds a curve, it is a)moving uniformly. b)accelerating. c)in rotational equilibrium. d)changing its speed.

37. © 2013 Pearson Education, Inc. When a car rounds a curve, it is a)moving uniformly. b)accelerating. c)in rotational equilibrium. d)changing its speed.

38. © 2013 Pearson Education, Inc. When a bird flies at 8 km/h in an 8-km/h headwind (moving against the wind), the speed of the bird relative to the ground is a)zero. b)8 km/h. c)16 km/h. d)more than 16 km/h.

39. © 2013 Pearson Education, Inc. When a bird flies at 8 km/h in an 8-km/h headwind (moving against the wind), the speed of the bird relative to the ground is a)zero. b)8 km/h. c)16 km/h. d)more than 16 km/h. Comment: And if it turns around and flies with the wind, its ground speed will be 16 km/h.

40. © 2013 Pearson Education, Inc. If a bus increases its speed by 4 km/h each second, its acceleration is a)4 km/h. b)4 km/h per second. c)4 m/s per second. d)4 m/s.

41. © 2013 Pearson Education, Inc. If a bus increases its speed by 4 km/h each second, its acceleration is a)4 km/h. b)4 km/h per second. c)4 m/s per second. d)4 m/s.

42. © 2013 Pearson Education, Inc. When a ball rolling down an inclined plane gains 4 m/s each second, the acceleration of the ball is a)0. b)4 m/s. c)4 m/s 2. d)none of the above.

43. © 2013 Pearson Education, Inc. When a ball rolling down an inclined plane gains 4 m/s each second, the acceleration of the ball is a)0. b)4 m/s. c)4 m/s 2. d)none of the above.

44. © 2013 Pearson Education, Inc. A body undergoes acceleration whenever there is a change in its a)speed. b)velocity. c)direction. d)all of the above.

45. © 2013 Pearson Education, Inc. A body undergoes acceleration whenever there is a change in its a)speed. b)velocity. c)direction. d)all of the above. Explanation: The figure says it all!

46. © 2013 Pearson Education, Inc. A ball simultaneously begins rolling along equal- length tracks A and B. It will roll faster when a)in the dip of track B. b)at the end of track B. c)either in the dip or at the end of track B. d)at the end of track A.

47. © 2013 Pearson Education, Inc. A ball simultaneously begins rolling along equal- length tracks A and B. It will roll faster when a)in the dip of track B. b)at the end of track B. c)either in the dip or at the end of track B. d)at the end of track A.

48. © 2013 Pearson Education, Inc. A ball rolls along equal-length tracks A and B. Due to increased speed in the dip, it will have an overall greater average speed on track a)A. b)B. c)Both the same. d)Neither of the above.

49. © 2013 Pearson Education, Inc. A ball rolls along equal-length tracks A and B. Due to increased speed in the dip, it will have an overall greater average speed on track a)A. b)B. c)Both the same. d)Neither of the above.

50. © 2013 Pearson Education, Inc. A ball rolls along equal-length tracks A and B. It will reach the end of track B a)sooner than along track A. b)at the same time as along track A. c)later than along track A d)none of these make sense.

51. © 2013 Pearson Education, Inc. A ball rolls along equal-length tracks A and B. It will reach the end of track B a)sooner than along track A. b)at the same time as along track A. c)later than along track A d)none of these make sense. Comment: So Ball B wins the race, but at the same final speed!

52. © 2013 Pearson Education, Inc. If you drop a boulder from a tall cliff, as it falls it will gain a)10 m/s of speed each second. b)more and more speed each second. c)equal amount of falling distance each second. d)all of the above.

53. © 2013 Pearson Education, Inc. If you drop a boulder from a tall cliff, as it falls it will gain a)10 m/s of speed each second. b)more and more speed each second. c)equal amount of falling distance each second. d)all of the above. Comment: Answer B is incorrect, for a boulder in free fall gains the same amount of speed each second.

54. © 2013 Pearson Education, Inc. After being dropped from the top of a high building, a free-falling object has a speed of 30 m/s at one instant. Exactly 1 second earlier, its speed was a)the same. b)10 m/s. c)20 m/s. d)40 m/s.

55. © 2013 Pearson Education, Inc. After being dropped from the top of a high building, a free-falling object has a speed of 30 m/s at one instant. Exactly 1 second earlier, its speed was a)the same. b)10 m/s. c)20 m/s. d)40 m/s. Explanation: A free-falling object changes its speed by 10 m/s each second. 30 m/s – 10 m/s = 20 m/s. If it were moving upward, technically still in "free fall," its speed 1 second earlier would be 40 m/s.

56. © 2013 Pearson Education, Inc. Toss a ball straight upward, and each second on the way to the top it a)loses 10 m/s in speed. b)accelerates upward. c)both of the above. d)neither of the above.

57. © 2013 Pearson Education, Inc. Toss a ball straight upward, and each second on the way to the top it a)loses 10 m/s in speed. b)accelerates upward. c)both of the above. d)neither of the above.

58. © 2013 Pearson Education, Inc. When a ball is tossed straight upward, the direction of its acceleration is a)upward also. b)downward, toward Earth's center. c)actually horizontal. d)at some sort of a strange angle.

59. © 2013 Pearson Education, Inc. When a ball is tossed straight upward, the direction of its acceleration is a)upward also. b)downward, toward Earth's center. c)actually horizontal. d)at some sort of a strange angle.

60. © 2013 Pearson Education, Inc. The longest that anyone in your school can be in the air when jumping straight upward, landing at the same place, is a)less than 1 second. b)about 1 second. c)about 2 seconds. d)more than 2 seconds.

61. © 2013 Pearson Education, Inc. The longest that anyone in your school can be in the air when jumping straight upward, landing at the same place, is a)less than 1 second. b)about 1 second. c)about 2 seconds. d)more than 2 seconds. Comment: Even basketball superstars have a hang time of less than 1 second.