1. Universe Tenth Edition Chapter 4 Gravitation and the Waltz of Planets Roger Freedman Robert Geller William Kaufmann III Clicker Questions

2. When Jupiter is at opposition (see diagram), it is overhead (i.e., on the meridian) at A.6:00 A.M. B.12:00 noon. C.6:00 P.M. D.midnight. E.never at night. Q4.1

3. When Jupiter is at opposition (see diagram), it is overhead (i.e., on the meridian) at A.6:00 A.M. B.12:00 noon. C.6:00 P.M. D.midnight. E.never at night. A4.1

4. When Venus is in the position of greatest western elongation or greatest eastern elongation, its phase is a.quarter. b.gibbous. c.crescent. d.full. e.new. Q4.2

5. When Venus is in the position of greatest western elongation or greatest eastern elongation, its phase is a.quarter. b.gibbous. c.crescent. d.full. e.new. Q4.2

6. Epicycles are used in a geocentric model to explain the A.eastward motion of Mars. B.westward motion of Mars. C.phases of Venus. D.appearance of Venus in the early morning or late evening sky. E.phases of the moon. Q4.3

7. Epicycles are used in a geocentric model to explain the A.eastward motion of Mars. B.westward motion of Mars. C.phases of Venus. D.appearance of Venus in the early morning or late evening sky. E.phases of the moon. A4.3

8. When Venus is in the position of greatest western elongation (see diagram), it is A.a “ morning ” star (visible before sunrise). B.an “ evening ” star (visible after sunset). C.overhead at midnight. D.not visible from anywhere on Earth. E.overhead at noon. Q4.4

9. When Venus is in the position of greatest western elongation (see diagram), it is A.a “ morning ” star (visible before sunrise). B.an “ evening ” star (visible after sunset). C.overhead at midnight. D.not visible from anywhere on Earth. E.overhead at noon. A4.4

10. Kepler ’ s three laws A.were initially derived from fundamental physics laws. B.were initially found from observation and are empirical rules that describe how the planets move. C.were handed down from the ancient Greeks. D.were discovered by Kepler in ancient Babylonian texts. E.are now known to be grossly incorrect. Q4.5

11. Kepler ’ s three laws A.were initially derived from fundamental physics laws. B.were initially found from observation and are empirical rules that describe how the planets move. C.were handed down from the ancient Greeks. D.were discovered by Kepler in ancient Babylonian texts. E.are now known to be grossly incorrect. A4.5

12. A planet in an elliptical orbit around the Sun moves most rapidly when it is A.at aphelion. B.at perihelion. C.halfway between perihelion and aphelion. D.closer to aphelion than perihelion. E.None of the above; it has a constant speed. Q4.6

13. A planet in an elliptical orbit around the Sun moves most rapidly when it is A.at aphelion. B.at perihelion. C.halfway between perihelion and aphelion. D.closer to aphelion than perihelion. E.None of the above; it has a constant speed. A4.6

14. Two planets are in circular orbits around similar stars. Each is the same distance from its parent star. One planet is Jupiter ’ s size, whereas the other is Earth ’ s size. Which of the following is true? A.The Jupiter-size planet has a much longer period than the Earth-size planet. B.The Earth-size planet has a much longer period than the Jupiter-size planet. C.Both planets have the same period. D.The Earth-size planet has a period exactly twice that of the Jupiter-size planet. E.Not enough information is given to determine the correct answer. Q4.7

15. Two planets are in circular orbits around similar stars. Each is the same distance from its parent star. One planet is Jupiter ’ s size, whereas the other is Earth ’ s size. Which of the following is true? A.The Jupiter-size planet has a much longer period than the Earth-size planet. B.The Earth-size planet has a much longer period than the Jupiter-size planet. C.Both planets have the same period. D.The Earth-size planet has a period exactly twice that of the Jupiter-size planet. E.Not enough information is given to determine the correct answer. A4.7

16. If a moving object changes direction, then A.its velocity has changed and therefore it is accelerating. B.its velocity has changed but it is not accelerating. C.its velocity has not changed, and we cannot determine if it is accelerating because we do not know if the speed is changing. D.Not enough information is given to determine if the velocity is changing. Q4.8

17. If a moving object changes direction, then A.its velocity has changed and therefore it is accelerating. B.its velocity has changed but it is not accelerating. C.its velocity has not changed, and we cannot determine if it is accelerating because we do not know if the speed is changing. D.Not enough information is given to determine if the velocity is changing. Q4.8

18. Which of the following objects has zero acceleration? A.A car just starting out from a stop light B.A car traveling at 70 miles per hour on a long straight interstate highway C.A car exiting an interstate on a curved off-ramp D.A car slowing down for a red light E.A car skidding to a stop to avoid an accident Q4.9

19. Which of the following objects has zero acceleration? A.A car just starting out from a stop light B.A car traveling at 70 miles per hour on a long straight interstate highway C.A car exiting an interstate on a curved off-ramp D.A car slowing down for a red light E.A car skidding to a stop to avoid an accident Q4.9

20. Which one of the following objects has no net (total) force exerted on it? A.A car just starting out from a stop light B.A car traveling at 70 miles per hour on a long straight interstate highway C.A car exiting an interstate on a curved off-ramp D.A car slowing down for a red light E.A car skidding to a stop to avoid an accident Q4.10

21. Which one of the following objects has no net (total) force exerted on it? A.A car just starting out from a stop light B.A car traveling at 70 miles per hour on a long straight interstate highway C.A car exiting an interstate on a curved off-ramp D.A car slowing down for a red light E.A car skidding to a stop to avoid an accident Q4.10

22. Which of the following is correct concerning the force on and the motion of a planet? A.A planet moving at constant speed has no force exerted on it. B.A planet traveling at constant speed but changing direction of travel has a force exerted on it. C.A planet traveling with changing speed and changing direction of travel has a force exerted on it. D.Both B and C. E.A, B, and C are all correct. Q4.11

23. Which of the following is correct concerning the force on and the motion of a planet? A.A planet moving at constant speed has no force exerted on it. B.A planet traveling at constant speed but changing direction of travel has a force exerted on it. C.A planet traveling with changing speed and changing direction of travel has a force exerted on it. D.Both B and C. E.A, B, and C are all correct. A4.11

24. The gravitational force between the Earth and Sun is A.the same as the force between the Moon and Sun because the Earth and the Moon are the same distance from the Sun. B.larger than the gravitational force between the Moon and Sun because the Earth has a larger mass. C.smaller than the gravitational force between the Moon and Sun because the Earth has a larger mass. D.changes by a factor of four as we orbit the Sun. E.Not enough information is given to determine which is correct. Q4.12

25. The gravitational force between the Earth and Sun is A.the same as the force between the Moon and Sun because the Earth and the Moon are the same distance from the Sun. B.larger than the gravitational force between the Moon and Sun because the Earth has a larger mass. C.smaller than the gravitational force between the Moon and Sun because the Earth has a larger mass. D.changes by a factor of four as we orbit the Sun. E.Not enough information is given to determine which is correct. A4.12

26. If the distance between a planet and the Sun is doubled, how does the gravitational attraction between the two bodies change? A.It increases by a factor of 2. B.It increases by a factor of 4. C.It decreases by a factor of 2. D.It decreases by a factor of 4. E.Not enough information is provided. Q4.13

27. If the distance between a planet and the Sun is doubled, how does the gravitational attraction between the two bodies change? A.It increases by a factor of 2. B.It increases by a factor of 4. C.It decreases by a factor of 2. D.It decreases by a factor of 4. E.Not enough information is provided. Q4.13

28. The tidal force of the Moon on the Earth occurs because A.the Moon pulls more strongly on the near side of the Earth than the far side of the Earth. B.the Moon pulls more strongly on the far side of the Earth than the near side of the Earth. C.the Moon pulls equally strongly on the near side and the far side of the Earth. D.the Moon keeps its same face toward the Earth. E.the Moon is in a synchronous orbit. Q4.14

29. The tidal force of the Moon on the Earth occurs because A.the Moon pulls more strongly on the near side of the Earth than the far side of the Earth. B.the Moon pulls more strongly on the far side of the Earth than the near side of the Earth. C.the Moon pulls equally strongly on the near side and the far side of the Earth. D.the Moon keeps its same face toward the Earth. E.the Moon is in a synchronous orbit. A4.14