Study Guide_Final_PHS112_Pool01_answers.rtf

1) In contrast to Aristotle's way of explaining nature, Galileo relied on 1) _______ A) experiment. B) logic. C) mathematics. D) patterns.

A

11) A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the 11) ______ A) lead-filled ball. B) regular ball. C) same for both

A

16) Action and reaction pairs of forces always act on 16) ______ A) different bodies. B) the same body. C) either of these D) none of the above

A

3) The net force on any object moving at constant velocity is 3) _______ A) zero. B) equal to its weight. C) about half its weight. D) 10 meters per second squared.

A

31) A ball rolling down an incline has its maximum kinetic energy at 31) ______ A) the bottom. B) three-quarters of the way down. C) half-way down. D) the top.

A

32) A common pulley acts similar to a 32) ______ A) common lever. B) hydraulic press. C) gear. D) tension producer.

A

41) It is correct to say that impulse is equal to 41) ______ A) the change in momentum. B) momentum. C) the force multiplied by the distance the force acts. D) none of the above

A

42) When you can't escape being hit by a fast-moving object, you'll suffer a smaller force if the collision time is 42) ______ A) long. B) short. C) the same way either way

A

43) A karate chop is more effective if one's hand 43) ______ A) bounces upon impact. B) follows through upon impact. C) extends the time upon impact.

A

47) Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them 47) ______ A) increases. B) decreases. C) remains constant.

A

48) An object is placed exactly halfway between the Earth and the Moon. The object will fall toward the 48) ______ A) Earth. B) Moon. C) neither

A

49) Your weight is defined to be the force 49) ______ A) you exert against a supporting surface. B) due to gravity only. C) equal to your normal force on any surface.

A

50) Inside a freely-falling elevator you would have no 50) ______ A) weight. B) gravitational force on you. C) both of these D) none of the above

A

53) Dwarf planet Pluto was discovered by perturbations of 53) ______ A) Uranus and Neptune. B) Saturn. C) Jupiter. D) all of the above

A

54) A bullet fired from a rifle begins to fall 54) ______ A) as soon as it leaves the barrel. B) after air friction reduces its speed. C) neither of these

A

6) A constant net force on a railroad car produces constant 6) _______ A) acceleration. B) velocity. C) both of these D) neither of these

A

63) The fastest moving planet in a solar system is the 63) ______ A) planet nearest the Sun. B) planet farthest from the Sun. C) most massive planet. D) none of the above

A

67) An Earth satellite in an elliptical orbit travels slowest when it is 67) ______ A) farthest from the Earth. B) nearest the Earth. C) neither of these

A

8) If an object's mass is decreasing while a constant force is applied to the object, the acceleration 8) _______ A) increases. B) decreases. C) remains the same.

A

10) The air resistance of falling is greatly affected by an object's frontal area and 10) ______ A) mass. B) speed. C) weight.

B

13) Action and reaction forces are parts of 13) ______ A) multiple interactions. B) a single interaction. C) a pair of interactions.

B

17) The force exerted on the tires of a car to directly accelerate the car along a road is exerted by the 17) ______ A) air. B) road. C) engine. D) tires.

B

2) Inertia is defined as a 2) _______ A) change in motion. B) property of matter. C) force. D) none of the above

B

23) A cannonball fired from a long-barrel cannon will have a greater muzzle velocity because the cannonball receives a greater 23) ______ A) force. B) impulse. C) both of these D) none of the above

B

26) An object that has kinetic energy must be 26) ______ A) at an elevated position. B) moving. C) at rest. D) falling.

B

27) Power is defined as the 27) ______ A) force exerted divided by the time of exertion. B) work done divided by the time to do the work. C) force exerted multiplied by the distance moved. D) work done multiplied by the time to do the work.

B

28) If you do work on an object in half the time, your power output is 28) ______ A) the same. B) twice. C) half.

B

34) A machine puts out 100 W of power for every 1000 W put into it. The efficiency of the machine is 34) ______ A) 90%. B) 10%. C) 50%. D) 110%.

B

35) A jack system will increase the potential energy of a heavy load by no more than 1000 J with a work input of 2000 J. The efficiency of the jack system is at most 35) ______ A) 20%. B) 50%. C) 10%. D) 80%.

B

36) Which of these forms of energy is not renewable? 36) ______ A) solar power B) fossil fuel power C) photovoltaic power D) wind power

B

45) Newton discovered 45) ______ A) gravity. B) that gravity is universal. C) neither of these

B

5) Newton's second law focuses on 5) _______ A) speed. B) acceleration. C) velocity. D) none of the above

B

52) The planet Neptune was discovered by perturbations of 52) ______ A) Pluto. B) Uranus. C) its moons. D) none of the above

B

60) The Moon does not crash into Earth because 60) ______ A) the gravitational pull of other planets keeps the Moon up. B) the Moon has a sufficient tangential speed. C) the Moon has less mass than Earth. D) Earth's gravitational field is weak at the Moon's distance. E) none of the above

B

61) A "weightless" astronaut in an orbiting space vehicle is 61) ______ A) shielded from Earth's gravitational effects. B) without a support force. C) beyond the pull of gravity. D) none of the above

B

66) An Earth satellite in an elliptical orbit travels fastest when it is 66) ______ A) farthest from the Earth. B) nearest the Earth. C) neither of these

B

7) A given net force propels an object along a straight-line path. If the net force were doubled, its acceleration would 7) _______ A) be half. B) double. C) stay the same. D) quadruple.

B

12) After a ball tossed upward leaves your hand, the force of gravity on it 12) ______ A) changes direction. B) gradually increases. C) remains constant. D) gradually diminishes.

C

14) Earth exerts a force on the Moon. These two bodies make up 14) ______ A) multiple interactions. B) two interactions. C) one interaction.

C

15) A car traveling at 100 km/h strikes an unfortunate bug that splatters on the windshield. The force of impact is greater on the 15) ______ A) car. B) bug. C) same for both

C

19) An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater 19) ______ A) acceleration. B) speed. C) momentum. D) none of the above

C

20) It is correct to say that impulse is equal to 20) ______ A) the force multiplied by the distance the force acts. B) momentum. C) the change in momentum. D) none of the above

C

21) The conservation of momentum is most closely related to Newton's 21) ______ A) first law. B) second law. C) third law.

C

22) When bullets are fired in a forward direction from a fighter aircraft, the momentum of the aircraft 22) ______ A) increases. B) is unchanged. C) decreases.

C

24) The unit kilowatt-hour is a unit of 24) ______ A) power. B) time. C) energy. D) momentum.

C

25) An object may have potential energy because of its 25) ______ A) momentum. B) acceleration. C) location. D) speed.

C

30) A ball rolling down an incline has its maximum potential energy at 30) ______ A) a quarter of the way down. B) the bottom. C) the top. D) half-way down.

C

33) A simple machine cannot multiply 33) ______ A) distance. B) force. C) energy. D) none of the above

C

39) When you ride your scooter you have momentum. When you ride twice as fast you have 39) ______ A) almost twice the momentum. B) four times the momentum. C) twice the momentum. D) none of the above

C

40) An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater 40) ______ A) acceleration. B) speed. C) momentum. D) none of the above

C

44) The most energy per unit mass can be extracted from 44) ______ A) coal. B) petroleum. C) uranium. D) natural gas.

C

46) The Universal Gravitational Constant G was first measured by 46) ______ A) Newton. B) Galileo. C) Cavendish. D) none of these

C

55) A projectile is launched straight upward at 50 m/s. Neglecting air resistance its speed upon returning to its starting point is 55) ______ A) more than 50 m/s. B) less than 50 m/s. C) 50 m/s.

C

56) A ball rolls off the edge of a table at the same time another ball drops vertically from the same table. The ball to hit the floor first is the 56) ______ A) dropped ball. B) rolling ball. C) both hit at the same time

C

57) With no air resistance, a projectile fired at 60° has the same range as if it were fired at 57) ______ A) 45°. B) 15°. C) 30°. D) 75°.

C

59) An Earth satellite is simply a projectile 59) ______ A) approaching Earth from outer space. B) floating motionless in space near Earth. C) freely falling around Earth.

C

62) Compared with the period of satellites in orbit close to Earth, the period of satellites in orbit far from Earth is 62) ______ A) less. B) the same. C) greater. D) not enough information

C

64) A lunar month is about 28 days. If the Moon were farther from Earth than it is now, the lunar month would be 64) ______ A) less than 28 days. B) about 28 days. C) more than 28 days.

C

65) A lunar month is about 28 days. If the Moon were closer to Earth than it is now, the lunar month would be 65) ______ A) unchanged at 28 days. B) more than 28 days. C) less than 28 days.

C

68) Gravitational force is greater for a satellite in elliptical orbit when it is at the 68) ______ A) zenith. B) apogee (farthest point). C) perigee (closest point). D) same acceleration at all of the above places

C

18) A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is 18) ______ A) unchanged. B) quadrupled. C) zero. D) doubled.

D

29) When a bus brakes to a stop its kinetic energy transforms to 29) ______ A) energy of motion. B) stopping energy. C) energy of rest. D) heat.

D

37) The ultimate source of energy from fossil fuels is the 37) ______ A) radioactivity in Earth's interior. B) photosynthesis process. C) natural processes in Earth's interior. D) Sun.

D

38) The exhaust product from a hydrogen fuel cell is 38) ______ A) carbon dioxide. B) methane. C) nitric acid. D) pure water.

D

4) If your automobile runs out of fuel while driving, the engine stops. You don't come to an abrupt stop because of 4) _______ A) gravity. B) the principle of continuation. C) resistance. D) inertia.

D

51) Occupants of the International Space Station experience weightlessness due to 51) ______ A) rotation of the station. B) the absence of Earth gravity at that altitude. C) no inertia in space. D) the absence of a support force.

D

58) With no air resistance, a projectile fired at 50° has the same range as if it were fired at 58) ______ A) 45°. B) 55°. C) 60°. D) 40°.

D

9) Lillian pulls on a 25-kg cart with a constant force of 50 N. What is the wagon's acceleration? 9) _______ A) 5 m/s2 B) 0.2 m/s2 C) 20 m/s2 D) 2.0 m/s2

D