Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
What is the difference between a bound orbit and an unbound orbit around the Sun?
1)
A)
A bound orbit is circular, while an unbound orbit is elliptical.
B)
An object on a bound orbit follows the same path around the Sun over and over, while an
object on an unbound orbit approaches the Sun just once and then never returns.
C)
A bound orbit is an orbit allowed by the universal law of gravitation, and an unbound orbit is
not.
D)
An object on a bound orbit has a gravitational attraction to the Sun, while an object on an
unbound orbit does not.
2)
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?
2)
A)
6 months
B)
1 year
C)
2 years
D)
It cannot be determined from the information given.
3)
Considering Einstein’s famous equation, E = mc2, which of the following statements is true?
3)
A)
Mass can be turned into energy, but energy cannot be turned back into mass.
B)
A small amount of mass can be turned into a large amount of energy.
C)
One kilogram of mass represents 1 joule of energy.
D)
You can make mass into energy if you can accelerate the mass to the speed of light.
E)
It takes a large amount of mass to produce a small amount of energy.
4)
The tides on Earth are an example of
4)
A)
Newton’s first law of motion.
B)
Newton’s second law of motion.
C)
Newton’s third law of motion.
D)
the universal law of gravitation.
E)
none of the above
5)
Why are astronauts weightless in the Space Station?
5)
A)
because the Space Station is traveling so fast
B)
because the Space Station is constantly in free–fall around the Earth
C)
because there is no gravity in space
D)
because the Space Station is moving at constant velocity
B
6)
What quantities does angular momentum depend upon?
6)
A)
mass, velocity, and radius
B)
force and radius
C)
mass and velocity
D)
momentum and angular velocity
E)
force, velocity, and radius
A
7)
Suppose you heat an oven to 400°F and boil a pot of water. Which of the following explains why
you would be burned by sticking your hand briefly in the pot but not by sticking your hand briefly
in the oven?
7)
A)
The molecules in the water are moving faster than the molecules in the oven.
B)
The water can transfer heat to your arm more quickly than the air.
C)
The water has a higher temperature than the oven.
D)
The oven has a higher temperature than the water.
B
D
8)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
According to this, what observational information does one need in order to calculate the combined
mass of a planet and its moon?
8)
A)
the average distance between the two objects and the orbital period
B)
the radius of the two planets in meters and the average distance between them
C)
the orbital period and the density of the two objects
D)
It is impossible to determine the mass of any astronomical object.
9)
A planet is orbiting a star. Which of the following statements is true for the acceleration and
gravitational forces experienced by the star and the planet?
9)
A)
The acceleration of the planet is much more than the acceleration of the star, and the force on
the planet is much more than the force on the star.
B)
The acceleration of the planet is much more than the acceleration of the star, but the force on
the star is the same but opposite the force on the planet.
C)
The force on the star is much smaller than the force on the planet, but the accelerations are
about equal.
10)
If an object‘s velocity is doubled, its momentum is
10)
A)
doubled.
B)
dependent on its acceleration.
C)
quadrupled.
D)
halved.
E)
unchanged.
11)
According to the universal law of gravitation, if you triple the distance between two objects, then
the gravitational force between them ________.
11)
A)
increases by a factor of 9
B)
increases by a factor of 3
C)
decreases by a factor of 9
D)
decreases by a factor of 3
12)
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?
12)
A)
The 5–pound weight will hit the ground before the 10–pound weight.
B)
Both will hit the ground at the same time.
C)
The 10–pound weight will hit the ground before the 5–pound weight.
D)
Both weights will float freely, since everything is weightless on the Moon.
13)
Consider the elliptical orbit of a comet around the Sun. Where in its orbit does it have the largest
amount of total orbital energy?
13)
A)
when it is farthest from the Sun
B)
when it is closest to the Sun
C)
It always has the same total orbital energy.
14)
Which of the following statements correctly describes the law of conservation of energy?
14)
A)
Energy can change between many different forms, such as potential, kinetic, and thermal, but
it is ultimately destroyed.
B)
It is not really possible for an object to gain or lose potential energy because energy cannot be
destroyed.
C)
The fact that you can fuse hydrogen into helium to produce energy means that helium can be
turned into hydrogen to produce energy.
D)
The total quantity of energy in the universe never changes.
E)
An object always has the same amount of energy.
15)
As long as an object is not gaining or losing mass, a net force on the object will cause a change in
15)
A)
weight.
B)
velocity.
C)
direction.
D)
speed.
E)
acceleration.
16)
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?
16)
A)
The spacecraft breaks apart, and the pieces continue to orbit the planet.
B)
The spacecraft breaks in half and begins to sink down into the planet, like a sinking aircraft
carrier.
C)
The spacecraft burns up in a giant reball.
17)
Where does the energy come from that your body uses to keep you alive?
17)
A)
It is in the air that you breathe.
B)
It is created during the time that you rest or sleep.
C)
It is produced from the radiative energy of the Sun on your skin.
D)
It comes from the water you drink.
E)
It comes from the foods you eat.
E
18)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
In this equation, what does a represent?
18)
A)
the orbital period
B)
the average distance between the two objects
C)
the masses of the two objects
D)
the universal gravitational constant
B
19)
Momentum is defined as ________.
19)
A)
mass times speed
B)
mass times velocity
C)
force times velocity
D)
mass times acceleration
B
A
20)
What is the acceleration of gravity at the surface of Earth?
20)
A)
9.8 km/s downward
B)
9.8 m/s2 downward
C)
9.8 m/s downward
D)
9.8 m2/s downward
E)
9.8 km/s2 downward
21)
Gasoline is useful in cars because it has
21)
A)
radiative energy.
B)
gravitational potential energy.
C)
kinetic energy.
D)
electrical potential energy.
E)
chemical potential energy.
22)
The force due to gravity between two objects can be described using the equation Fg= G M1 M2 /
d2. In this equation, what does d represent?
22)
A)
the density of the smaller object
B)
the distance between the two objects
C)
the universal gravitational constant
23)
If a gas cloud shrinks, its gravitational potential energy is converted into
23)
A)
kinetic energy and sound waves.
B)
chemical energy.
C)
only radiative energy.
D)
thermal energy and radiative energy.
24)
The allowed shapes for orbits under the force of gravity are
24)
A)
ellipses, spirals, and parabolas.
B)
ellipses, parabolas, and hyperbolas.
C)
spirals, circles, and squares.
D)
ellipses only.
E)
ellipses and spirals.
25)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
In this equation, what does p represent?
25)
A)
the orbital period
B)
the average distance between the two objects
C)
the masses of the two objects
D)
the universal gravitational constant
26)
The difference between speed and velocity is that ________.
26)
A)
velocity is the same as acceleration but speed is different
B)
velocity also includes a direction
C)
velocity is calculated using a physics equation
D)
they are expressed in different units
27)
What does temperature measure?
27)
A)
the average mass of particles in a substance
B)
the average kinetic energy of particles in a substance
C)
the total amount of heat in a substance
D)
the total potential energy of particles in a substance
28)
Why is Newton’s version of Kepler’s third law so useful to astronomers?
28)
A)
It tells us that more–distant planets orbit the Sun more slowly.
B)
It explains why objects spin faster when they shrink in size.
C)
It allows us to calculate distances to distant objects.
D)
It can be used to determine the masses of many distant objects.
29)
The speed at which a pool ball moves after being struck by a cue is most directly an example of
29)
A)
Newton’s first law of motion.
B)
Newton’s second law of motion.
C)
Newton’s third law of motion.
D)
the universal law of gravitation.
30)
Suppose the Sun were suddenly to shrink in size but that its mass remained the same. According to
the law of conservation of angular momentum, what would happen?
30)
A)
The Sun would rotate faster than it does now.
B)
The Sun’s angular size in our sky would stay the same.
C)
The Sun’s rate of rotation would slow.
D)
This could never happen, because it is impossible for an object to shrink in size without an
outside torque.
31)
The force due to gravity between two objects can be described using the equation Fg= G M1 M2 /
d2. According to this equation, if the mass of the second object were greater, what happens to the
gravitational force between them?
31)
A)
The force increases.
B)
The force decreases.
C)
The force drops instantly to zero.
D)
The gravitational force is not affected by the mass of the second object.
32)
The energy attributed to an object by virtue of its motion is known as ________.
32)
A)
potential energy
B)
mass–energy
C)
radiative energy
D)
kinetic energy
33)
The force due to gravity between two objects can be described using the equation Fg= G M1 M2 /
d2. According to this equation, if the distance between two objects increases, what happens to the
gravitational force between them?
33)
A)
The force increases.
B)
The force decreases.
C)
The force drops instantly to zero.
D)
The gravitational force is not affected by distance.
34)
The fact that Voyager 10 continues to speed out of the solar system, even though its rockets have no
fuel, is an example of
34)
A)
Newton’s first law of motion.
B)
Newton’s second law of motion.
C)
Newton’s third law of motion.
D)
the universal law of gravitation.
E)
none of the above
35)
According to the universal law of gravitation, the force due to gravity is
35)
A)
directly proportional to the square of the distance between objects.
B)
not dependent on the distance between objects.
C)
directly proportional to the distance between objects.
D)
inversely proportional to the square of the distance between objects.
E)
inversely proportional to the distance between objects.
36)
The force due to gravity between two objects can be described using the equation Fg= G M1 M2 /
d2. In this equation, what does M1 represent?
36)
A)
the diameter, in meters, of one of the objects
B)
the mass of one of the objects
C)
the distance, in meters, between the two objects
37)
The planets never travel in a straight line as they orbit the Sun. According to Newton’s second law
of motion, this must mean that ________.
37)
A)
the planets are always accelerating
B)
the planets will eventually fall into the Sun
C)
the planets have angular momentum
D)
a force is acting on the planets
38)
A net force acting on an object will always cause a change in the object’s ________.
38)
A)
mass
B)
direction
C)
momentum
D)
speed
39)
Which of the following statements is not one of Newton’s Laws of Motion?
39)
A)
In the absence of a net force acting upon it, an object moves with constant velocity.
B)
The rate of change of momentum of an object is equal to the net force applied to the object.
C)
For any force, there always is an equal and opposite reaction force.
D)
What goes up must come down.
40)
Each of the following lists two facts. Which pair of facts can be used with Newton’s version of
Kepler’s third law to determine the mass of the Sun?
40)
A)
Mercury is 0.387 AU from the Sun and Earth is 1 AU from the Sun.
B)
The mass of Earth is 6 × 1024 kg and Earth orbits the Sun in one year.
C)
Earth is 150 million km from the Sun and orbits the Sun in one year.
D)
Earth rotates in one day and orbits the Sun in one year.
41)
Suppose that the Sun shrank in size but that its mass remained the same. What would happen to
the orbit of the Earth?
41)
A)
Earth would change from a bound orbit to an unbound orbit and fly off into interstellar space.
B)
Earth’s orbit would be unaffected.
C)
Earth’s orbit would expand, and it would take more than one year to orbit the Sun.
D)
The size of Earth’s orbit would shrink, and it would take less than one year to orbit the Sun.
42)
When a spinning ice skater pulls in his arms, he spins faster because ________.
42)
A)
there is less friction with the air
B)
there is less friction with the ice
C)
there exists an unbalanced reaction force
D)
his angular momentum must be conserved, so reducing his radius must increase his speed of
rotation
43)
Which of the following best explains why the Moon’s orbital period and rotation period are the
same?
43)
A)
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.
B)
The equality of the Moon’s orbital and rotation periods is an extraordinary astronomical
coincidence.
C)
The Moon once rotated faster, but tidal friction slowed the rotation period until it matched the
orbital period.
D)
The Moon was once closer to Earth, but the force of gravity got weaker as the Moon moved
farther away.
44)
Suppose that a lone asteroid happens to be passing Jupiter on an unbound orbit (well above
Jupiter’s atmosphere and far from all of Jupiter’s moons.) Which of the following statements would
be true?
44)
A)
Jupiter’s gravity would suck in the asteroid, causing it to crash into Jupiter.
B)
The asteroid’s orbit around Jupiter would not change, and it would go out on the same
unbound orbit that it came in on.
C)
Jupiter’s gravity would capture the asteroid, making it a new moon of Jupiter.
D)
There is no way to predict what would happen.
45)
How does a rocket launch upwards? Choose the statement that best describes why a rocket goes
up.
45)
A)
By expelling gas downwards, the rocket is propelled upwards.
B)
By expelling gas, the rocket loses mass; because it is lighter, it rises up.
C)
By expelling gas downwards, which pushes against the ground, the rocket is propelled
upwards.
46)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
In this equation, what do M1 and M2 represent?
46)
A)
the orbital period
B)
the average distance between the two objects
C)
the masses of the two objects
D)
the universal gravitational constant
47)
Which of the following represents a case in which you are not accelerating?
47)
A)
slamming on the brakes to come to a stop at a stop sign
B)
driving 60 miles per hour around a curve
C)
driving in a straight line at 60 miles per hour
D)
going from 0 to 60 miles per hour in 10 seconds
48)
What would happen if the Space Shuttle were launched with a speed greater than Earth’s escape
velocity?
48)
A)
It would be in an unstable orbit.
B)
It would travel in a higher orbit around Earth.
C)
It would travel away from Earth into the solar system.
D)
It would take less time to reach its bound orbit.
E)
It would orbit Earth at a faster velocity.
49)
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?
49)
A)
10 m/s
B)
30 m/s
C)
30 m/s2
D)
10 m/s2
E)
20 m/s
50)
How does the Space Shuttle take off?
50)
A)
Its rocket engines push against the launch pad, propelling the shuttle upwards.
B)
Hot gas shoots out from the rocket and, by conservation of momentum, the shuttle moves in
the opposite direction.
C)
by achieving lift from its wings in the same way that airplanes do
D)
by converting mass–energy to kinetic energy
E)
The hot rocket exhaust expands the air beneath the shuttle, propelling it forward.
51)
The ultimate source of energy that powers the Sun is
51)
A)
kinetic energy of the orbital motion of the Sun.
B)
mass energy of hydrogen fusing into helium.
C)
gravitational potential energy of the contraction of the gas cloud that formed the Sun.
D)
chemical potential energy of hydrogen burning into helium.
E)
thermal energy of the hydrogen atoms in the Sun.
52)
A rock held above the ground has potential energy. As the rock falls, this potential energy is
converted to kinetic energy. Finally, the rock hits the ground and stays there. What has happened to
the energy?
52)
A)
The energy goes to producing sound and to heating the ground, rock, and surrounding air.
B)
The energy goes into the ground, and as a result, the orbit of the Earth about the Sun is
slightly changed.
C)
It is transformed back into gravitational potential energy.
D)
The rock keeps the energy inside it in the form of mass–energy.
53)
Suppose an object is moving in a straight line at 50 mi/hr. According to Newton’s first law of motion,
the object will
53)
A)
continue to move in the same way until it is acted upon by a force.
B)
continue to move in the same way forever, no matter what happens.
C)
eventually slow down and come to a stop.
D)
continue to move in a straight line forever if it is in space, but fall to the ground if it is on
Earth.
54)
At which lunar phase(s) are tides least pronounced (e.g., the lowest high tides)?
54)
A)
new moon
B)
first quarter
C)
full moon
D)
both new and full moons
E)
both first and third quarters
55)
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?
55)
A)
The ball’s gravitational potential energy is greatest at the instant the ball leaves your foot.
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 greatest at the instant when the ball is at its highest
point.
D)
The ball’s gravitational potential energy is always the same.
56)
According to the universal law of gravitation, if you double the masses of both attracting objects, then
the gravitational force between them will
56)
A)
decrease by a factor of 4.
B)
not change at all.
C)
increase by a factor of 4.
D)
increase by a factor of 2.
E)
decrease by a factor of 2.
57)
What do we mean by the orbital energy of an orbiting object (such as a planet, moon, or satellite)?
57)
A)
Orbital energy is the object’s kinetic energy as it moves through its orbit.
B)
Orbital energy is the amount of energy required for the object to leave orbit and escape into
space.
C)
Orbital energy is a measure of the object’s speed as it moves through its orbit.
D)
Orbital energy is the sum of the object’s kinetic energy and its gravitational potential energy
as it moves through its orbit.
58)
Newton’s second law states: sum of forces = mass × acceleration. According to this, what property can
you determine if you observe the acceleration of an object with a known mass?
58)
A)
the sum total of all forces acting on the object
B)
the current location of the object
C)
the current velocity of the object.
D)
the value of a single force acting on the object
59)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
In this equation, what does G represent?
59)
A)
the orbital period
B)
the average distance between the two objects
C)
the masses of the two objects
D)
the universal gravitational constant
60)
As an interstellar cloud of hydrogen gas shrinks in size, its temperature increases
60)
A)
because thermal energy is converted to radiative energy.
B)
because gravitational potential energy is converted to thermal energy.
C)
because kinetic energy is converted to radiative energy.
61)
The force due to gravity between two objects can be described using the equation Fg= G M1 M2 /
d2. In this equation, what does G represent?
61)
A)
the density of the smaller object
B)
the universal gravitational constant
C)
the distance between the two objects
62)
The amount of gravitational potential energy released as an object falls depends on
62)
A)
the distance it falls.
B)
its speed at the time it begins falling.
C)
neither the distance it falls nor its speed at the time it begins falling.
D)
the distance it falls and its speed at the time it begins falling.
63)
In which of the following cases would you feel weightless?
63)
A)
while falling from a roof
B)
while walking on the Moon
C)
while parachuting from an airplane
D)
while accelerating downward in an elevator
64)
According to what we now know from Newton’s laws, which of the following best explains why
Kepler’s second law is true?
64)
A)
This effect happens because of the influence of other planets on a particular planet’s orbit.
B)
A planet’s total orbital energy must be conserved as it moves around its orbit.
C)
Orbits must be elliptical in shape.
D)
Gravity is an inverse cube law.
65)
Changing the orbit of a spacecraft by firing thrusters is an example of
65)
A)
Newton’s first law of motion.
B)
Newton’s second law of motion.
C)
Newton’s third law of motion.
D)
the universal law of gravitation.
E)
none of the above
66)
The force of gravity is an inverse square law. This means that, if you double the distance between
two large masses, the gravitational force between them
66)
A)
weakens by a factor of 4.
B)
is unaffected.
C)
strengthens by a factor of 4.
D)
also doubles.
E)
weakens by a factor of 2.
67)
If your mass is 60 kg on Earth, what would your mass be on the Moon?
67)
A)
60 kg
B)
10 kg
C)
60 lb
D)
50 kg
E)
10 lb
68)
The mass of Jupiter can be calculated by
68)
A)
knowing the Sun’s mass and measuring how Jupiter’s speed changes during its elliptical orbit
around the Sun.
B)
measuring the orbital speed of one of Jupiter’s moons.
C)
measuring the orbital period and distance of Jupiter’s orbit around the Sun.
D)
knowing the Sun’s mass and measuring the average distance of Jupiter from the Sun.
E)
measuring the orbital period and distance of one of Jupiter‘s moons.
69)
You are standing on a scale in an elevator. Suddenly you notice your weight decreases. What do you
conclude?
69)
A)
The elevator is accelerating downwards.
B)
The elevator is moving at a constant velocity upwards.
C)
The elevator is accelerating upwards.
D)
The elevator is moving at a constant velocity downwards.
E)
Your diet is working.
A
70)
Newton showed that Kepler’s laws are ________.
70)
A)
seriously in error
B)
actually only three of seven distinct laws of planetary motion
C)
the key to proving that Earth orbits our Sun
D)
natural consequences of the law of universal gravitation
D
71)
Which statement must be true in order for a rocket to travel from Earth to another planet?
71)
A)
It must carry a lot of extra fuel.
B)
It must have very large engines.
C)
It must be launched from space, rather than from the ground.
D)
It must attain escape velocity from Earth.
D
E
72)
Suppose you are in an elevator that is traveling upward at constant speed. How does your weight
compare to your normal weight on the ground?
72)
A)
It is the same.
B)
It is greater.
C)
You are weightless.
D)
It is less.
73)
In the formula E =mc2, what does E represent?
73)
A)
the mass–energy, or potential energy stored in an object’s mass
B)
the kinetic energy of a moving object
C)
the gravitational potential energy of an object held above the ground
D)
the electric field produced by a charge
E)
the radiative energy carried by light
74)
Consider the elliptical orbit of a comet around the Sun. Where in its orbit is the comet moving the
fastest?
74)
A)
when it is closest to the Sun
B)
when it is farthest from the Sun
C)
It is always moving at the same speed.
75)
If a gas cloud shrinks, it
75)
A)
spins at the same rate as it did before it shrank.
B)
spins slower.
C)
spins faster.
76)
Newton’s version of Kepler’s third law states: p2=2
G(M1+ M2)×a3
Solve this equation to find the combined mass of a planet and its satellite, given the orbital period
and average separation.
76)
A)
M1+ M2 =42×a3
p2
B)
M1+ M2 =2
G×a3
p2
C)
M1+ M2 =G
2×p2
a3
D)
M1+ M2 =G
2×a3
p2
77)
Imagine another solar system, with a star more massive than the Sun. Suppose a planet with the
same mass as Earth orbits at a distance of 1 AU from the star. How would the planet’s year (orbital
period) compare to Earth’s year?
77)
A)
The planet’s year would be shorter than Earth’s.
B)
The planet’s year would be longer than Earth’s.
C)
An orbit at a distance of 1 AU would not be possible around a star more massive than the
Sun.
D)
The planet’s year would be the same as Earth’s.
Explanation:
78)
Approximately where is it currently high tide on Earth?
78)
A)
anywhere that ocean water laps upon the shore
B)
wherever it is currently noon
C)
only on the portion of the Earth facing directly toward the Moon
D)
on the portion of Earth facing directly toward the Moon and on the portion of Earth facing
directly away from the Moon
Explanation:
Explanation:
79)
The astronauts feel weightless in the International Space Station, which orbits the Earth once every
90 minutes. Why?
79)
A)
because the gravity from the Moon cancels out the gravity from Earth
B)
because there is no gravity in space
C)
because they are moving so fast
D)
because they and the space station are both falling around the Earth
80)
Suppose that two objects collide. Which of the following things is not the same both before and after
the collision?
80)
A)
the total temperature of the objects
B)
the total momentum of the objects
C)
the total energy of the objects
D)
the total angular momentum of the objects
A
81)
As an interstellar cloud of hydrogen gas shrinks in size, its rate of rotation
81)
A)
increases, because its total energy is conserved.
B)
increases, because its angular momentum is conserved.
C)
decreases, because its angular momentum is conserved.
D)
decreases, because the force of gravity strengthens as the cloud shrinks.
E)
increases, because the force of gravity strengthens as the cloud shrinks.
B
82)
At which lunar phase(s) are tides most pronounced (for example, the highest high tides)?
82)
A)
both new and full moons
B)
new moon only
C)
full moon only
D)
both first and third quarters
A
D
83)
Newton’s second law states: sum of forces = mass × acceleration. If a known force was applied to an
object with a known mass, how would you predict that object’s acceleration?
83)
A)
acceleration = mass / sum of forces
B)
acceleration = mass × sum of forces
C)
acceleration = sum of forces / mass
D)
Newton’s second law is irrelevant for solving this problem.
84)
Which of the following best describes the origin of ocean tides on Earth?
84)
A)
Tides are caused by the difference in the force of gravity exerted by the Moon across the
sphere of the Earth.
B)
Tides are caused by the 23.5–degree tilt of the Earth’s rotational axis to the ecliptic plane.
C)
The Moon’s gravity pulls harder on water than on land, because water is less dense than rock.
D)
Tides are caused on the side of the Earth nearest the Moon because the Moon’s gravity attracts
the water.
85)
Which of the following scenarios involves energy that we would typically calculate with Einstein’s
formula E =mc2?
85)
A)
A burning piece of wood produces light and heat, therefore giving off radiative and thermal
energy.
B)
A mass raised to a great height has a lot of gravitational potential energy.
C)
A small amount of the hydrogen in a nuclear bomb becomes energy as fusion converts the
hydrogen to helium.
D)
An object accelerated to a great speed has a lot of kinetic energy.
86)
Newton’s Second Law of Motion tells us that the net force applied to an object equals its ________.
86)
A)
momentum times velocity
B)
mass times acceleration
C)
mass times velocity
D)
mass times energy
87)
The gravitational force that the Earth exerts on the Moon is equal and opposite to that which the
Moon exerts on the Earth. Therefore, according to Newton’s second law of motion,
87)
A)
the Earth has a larger acceleration than the Moon, because it has a larger mass.
B)
the Moon and the Earth both have equal accelerations, because the forces are equal.
C)
the Moon has a larger acceleration than the Earth, because it has a smaller mass.
88)
Suppose you lived on the Moon. Which of the following would be true?
88)
A)
Your mass would be less than your mass on Earth, but your weight would be the same as it is
on Earth.
B)
Both your weight and your mass would be the same as they are on Earth.
C)
Your weight would be less than your weight on Earth, but your mass would be the same as it
is on Earth.
D)
Both your weight and your mass would be less than they are on Earth.
Explanation:
89)
0 degrees Kelvin is
89)
A)
the temperature at which all particles move at the speed of light.
B)
meaningless, a temperature outside the range defined for the Kelvin scale.
C)
the temperature at which all random particle motion stops.
D)
the temperature at which all particles transform into light.
Explanation:
90)
Radiative energy is ________.
90)
A)
energy carried by light
B)
energy from nuclear power plants
C)
energy of motion
D)
heat energy
Explanation:
Explanation:
91)
When space probe Voyager 2 passed by Saturn, its speed increased (but not due to firing its
engines). What must have happened?
91)
A)
Voyager 2 must have dipped through Saturn’s atmosphere.
B)
Saturn must have lost a very tiny bit of its orbital energy.
C)
Saturn’s rotation must have sped up slightly.
D)
Saturn must have captured an asteroid at precisely the moment that Voyager 2 passed by.
92)
Absolute zero is ________.
92)
A)
0° Celsius
B)
0° Fahrenheit
C)
100° Celsius
D)
0 Kelvin
93)
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.
93)
A)
The bowling ball will hit the ground before the golf ball.
B)
The golf ball will hit the ground before the bowling ball.
C)
The golf ball and the bowling ball will hit the ground at the same time.
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
94)
Explain what synchronous rotation is. What is it caused by? Give an example.
94)
95)
Suppose a satellite is in a low–Earth orbit. Is it possible that the satellite will eventually fall
to the ground? Why or why not?
95)
96)
State Newton’s three laws of motion.
96)
97)
A popular end for many cartoon characters is to fall into a “bottomless pit” in which the
unfortunate character will fall forever. Consider the space shuttle in orbit around the Earth.
Argue that there is a strong analogy between the cartoon “bottomless pit” and the orbital
motion of the shuttle.
97)
98)
Give an example in which kinetic energy can be converted to thermal energy.
98)
99)
Suppose it takes 6 seconds for a watermelon to fall to the ground after being dropped from
a tall building. If there were no air resistance, so that the watermelon would fall with the
acceleration of gravity, about how fast would it be going when it hit the ground?
99)
100)
Imagine another solar system, with a star of the same mass as the Sun. Suppose there is a
planet in that solar system with a mass double that of Earth orbiting at a distance of 1 AU
from the star. Thinking about Newton’s version of Kepler’s third law, what
(approximately) is the orbital period of this planet? Explain your answer.
100)
101)
Under what conditions is an object weightless?
101)
102)
Give an example in which thermal energy might be converted to gravitational energy.
102)
103)
Briefly explain why Earth feels a greater tidal force from the Moon than from the Sun, even
though it feels a greater gravitational force from the Sun.
103)
TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.
104)
Unbound orbits have more orbital energy than bound orbits.
104)
105)
The Moon is constantly falling toward Earth.
105)
106)
To measure the mass of an astronomical object, one can observe the orbital period and distance of a
companion.
106)
107)
When energy is converted from one form to another, a tiny amount is inevitably lost.
107)
108)
There is no gravity in space.
108)
109)
Doubling the distance between two objects halves the gravitational force between them.
109)
110)
The escape velocity from Earth is greater for larger rockets than for small ones.
110)
111)
Kepler deduced his laws of planetary motion once Newton had published his universal law of
gravitation.
111)
112)
Speed and velocity are the same thing.
112)
113)
The Moon is slowly moving away from Earth.
113)
114)
If you double the mass of fusion material in a hydrogen bomb, you quadruple the amount of
energy generated.
114)
115)
When you experience a downward gravitational force from the Earth, the Earth experiences a
weaker upward gravitational force from you.
115)
116)
Planets with larger orbital radii have longer orbital periods because they both have a longer
distance to travel in each orbit and move more slowly.
116)
117)
Planets with larger orbital radii have longer orbital periods only because they have a longer
distance to travel in each orbit.
117)
118)
Tidal friction caused by Earth’s stretching from the Moon’s gravity is gradually slowing down the
rotation of Earth.
118)
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
119)
Using equations: The force due to gravity between two objects can be described using the equation
Fg= G M1 M2 / d2. How would one use Newton’s second law to setup an equation one could use to find the
gravitational acceleration experienced by an isolated astronaut 10,000 km from the Earth’s center?
120)
Do Things We Cannot Directly Detect Exist? In the early part of the 20th century, physicists experimentally
discovered that a certain type of radioactive decay did not seem to conserve either energy or momentum. These
experiments were “explained” by postulating the existence of an undetected (and potentially undetectable)
particle, dubbed the neutrino, that carried away the missing energy and momentum. It was argued that
neutrinos interacted so weakly with matter that they were extremely hard to detect. If you were a scientist at
this time, how would you evaluate the reasonableness this solution given Occam’s razor?
121)
Argument by Analogy: A friend of yours is convinced of the influence of the Moon on everyday human affairs.
He cites a supposed correlation between crime and the occurrence of a full moon as proof. He even speculates
that the gravitational influence of the Moon is the mechanism by noting that it is the gravitational pull of the
Moon that causes the tides. “After all“, he argues, “as over half a human’s weight is water, the Moon must affect
the flow of blood in human beings!” How would you explain to your friend that this analogy, between the ocean
tides and water in the human body, is profoundly flawed. Are there any alternate explanations for a link
between moon phase and crime?
122)
Hallmarks of a Scientific Theory: All great scientific theories explain existing observations, unify and extend
existing concepts, and make new and novel predictions that can be experimentally tested. Using Newton’s
postulate of universal gravitation as a case study, explicitly demonstrate how it satisfies each of these criteria.
Answer Key
Testname: C4
29
Answer Key
Testname: C4
30
Answer Key
Testname: C4