Question 1

Suppose you drop a 10-pound weight and a 5-pound weight on the Moon, both from the same height at the same time. What will happen?

Accepted Answer

A)   Both will hit the ground at the same time.
B)   The 10-pound weight will hit the ground before the 5-pound weight.
C)   The 5-pound weight will hit the ground before the 10-pound weight.
D)   Both weights will float freely, since everything is weightless on the Moon. A

Question 2

Suppose that the Sun shrank in size but that its mass remained the same. What would happen to the orbit of the Earth?

Accepted Answer

A)   Earth's orbit would be unaffected.
B)   The size of Earth's orbit would shrink, and it would take less than one year to orbit the Sun.
C)   Earth's orbit would expand, and it would take more than one year to orbit the Sun.
D)   Earth would change from a bound orbit to an unbound orbit and fly off into interstellar space. A

Question 3

Imagine a Star Wars type spaceship in orbit around a planet. Its engine suffers a severe malfunction, and explodes. What is the most physically realistic depiction of this event?

Accepted Answer

A)   The spacecraft breaks in half, and begins to sink down into the planet, like a sinking aircraft carrier.
B)   The spacecraft breaks apart, and the pieces continue to orbit the planet.
C)   The spacecraft burns up in a giant ﬁreball. B

Question 4

If a gas cloud shrinks its gravitational potential energy is converted into

Accepted Answer

A)   chemical energy.
B)   only radiative energy.
C)   kinetic energy and sound waves.
D)   thermal energy and radiative energy.

Question 5

Under what conditions is an object weightless?

Accepted Answer

The answer of Under what conditions is an object weightless?...

Question 6

Speed and velocity are the same thing.

Accepted Answer

A) True 
 B)False

Question 7

How does a rocket launch upwards? Choose the statement that best describes why a rocket goes up.

Accepted Answer

A)   By expelling gas downwards, the rocket is propelled upwards
B)   Expelling gas downwards, which by pushing against the ground, propels the rocket upwards

Question 8

Imagine another solar system, with a star of the same mass as the Sun. Suppose a planet with a mass twice that of Earth (2MEₐᵣth) orbits at a distance of 1 AU from the star. What is the orbital period of this planet?

Accepted Answer

A)   1 year
B)   6 months
C)   2 years
D)   It cannot be determined from the information given.

Question 9

In the formula E=mc², what does E represent?

Accepted Answer

A)   The mass-energy, or potential energy stored in an object's mass
B)   The kinetic energy of a moving object
C)   The radiative energy carried by light
D)   The gravitational potential energy of an object held above the ground
E)   The electric field produced by a charge

Question 10

The escape velocity from Earth is greater for larger rockets than for small ones.

Accepted Answer

A) True 
 B)False

Question 11

Suppose you kick a soccer ball straight up to a height of 10 meters. Which of the following is true about the gravitational potential energy of the ball during its flight?

Accepted Answer

A)   The ball's gravitational potential energy is greatest at the instant when the ball is at its highest point.
B)   The ball's gravitational potential energy is greatest at the instant it returns to hit the ground.
C)   The ball's gravitational potential energy is always the same.
D)   The ball's gravitational potential energy is greatest at the instant the ball leaves your foot.

Question 12

Newton showed that Kepler's laws are ________.

Accepted Answer

A)   natural consequences of the law of universal gravitation
B)   seriously in error
C)   actually only three of seven distinct laws of planetary motion
D)   the key to proving that Earth orbits our Sun

Question 13

If I drop a golf ball and a bowling ball simultaneously from same height above the ground, what will happen? Neglect the effects of wind or air resistance.

Accepted Answer

A)   The golf ball and the bowling ball will hit the ground at the same time.
B)   The bowling ball will hit the ground before the golf ball.
C)   The golf ball will hit the ground before the bowling ball.

Question 14

The acceleration of gravity on Earth is approximately 10 m/s² (more precisely, 9.8 m/s²). If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?

Accepted Answer

A)   30 m/s
B)   10 m/s
C)   30 m/s²
D)   10 m/s²
E)   20 m/s

Question 15

If a gas cloud shrinks, it

Accepted Answer

A)   spins at the same rate as it did before it shrank.
B)   spins faster.
C)   spins slower.

Question 16

Which of the following best explains why the Moon's orbital period and rotation period are the same?

Accepted Answer

A)   The Moon once rotated faster, but tidal friction slowed the rotation period until it matched the orbital period.
B)   The Moon was once closer to Earth, but the force of gravity got weaker as the Moon moved farther away.
C)   The law of conservation of angular momentum ensured that the Moon must have the same amount of rotational angular momentum as it has of orbital angular momentum.
D)   The equality of the Moon's orbital and rotation periods is an extraordinary astronomical coincidence.

Question 17

Kepler deduced his laws of planetary motion once Newton had published his universal law of gravitation.

Accepted Answer

A) True 
 B)False

Question 18

Suppose you lived on the Moon. Which of the following would be true?

Accepted Answer

A)   Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth.
B)   Both your weight and your mass would be less than they are on Earth.
C)   Your mass would be less than your mass on Earth, but your weight would be the same as it is on Earth.
D)   Both your weight and your mass would be the same as they are on Earth.

Question 19

Which of the following best describes the origin of ocean tides on Earth?

Accepted Answer

A)   Tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the Earth.
B)   The Moon's gravity pulls harder on water than on land, because water is less dense than rock.
C)   Tides are caused by the 23.5-degree tilt of the Earth's rotational axis to the ecliptic plane.
D)   Tides are caused on the side of the Earth nearest the Moon because the Moon's gravity attracts the water.

Question 20

If you double the mass of fusion material in a hydrogen bomb, you quadruple the amount of energy generated.

Accepted Answer

A) True 
 B)False

Exam 4: Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Suppose you drop a 10-pound weight and a 5-pound weight on the Moon, both from the same height at the same time. What will happen?

Suppose that the Sun shrank in size but that its mass remained the same. What would happen to the orbit of the Earth?

Imagine a Star Wars type spaceship in orbit around a planet. Its engine suffers a severe malfunction, and explodes. What is the most physically realistic depiction of this event?

If a gas cloud shrinks its gravitational potential energy is converted into

Under what conditions is an object weightless?

Speed and velocity are the same thing.

How does a rocket launch upwards? Choose the statement that best describes why a rocket goes up.

Imagine another solar system, with a star of the same mass as the Sun. Suppose a planet with a mass twice that of Earth (2MEₐᵣth) orbits at a distance of 1 AU from the star. What is the orbital period of this planet?

In the formula E=mc², what does E represent?

The escape velocity from Earth is greater for larger rockets than for small ones.

Suppose you kick a soccer ball straight up to a height of 10 meters. Which of the following is true about the gravitational potential energy of the ball during its flight?

Newton showed that Kepler's laws are ________.

If I drop a golf ball and a bowling ball simultaneously from same height above the ground, what will happen? Neglect the effects of wind or air resistance.

The acceleration of gravity on Earth is approximately 10 m/s² (more precisely, 9.8 m/s²) . If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?

If a gas cloud shrinks, it

Which of the following best explains why the Moon's orbital period and rotation period are the same?

Kepler deduced his laws of planetary motion once Newton had published his universal law of gravitation.

Suppose you lived on the Moon. Which of the following would be true?

Which of the following best describes the origin of ocean tides on Earth?

If you double the mass of fusion material in a hydrogen bomb, you quadruple the amount of energy generated.