51) Why did 

52) Suppose the
gravitational force between two massive spheres is 20 N. If the distance
between the spheres is doubled, what is the force between the masses? 

53) Suppose the
gravitational force between two massive spheres is 20 N. If the magnitude of
each mass doubles, what is the force between the masses? 

54) Since Earth
is attracted to the sun, why doesn’t it fall into the sun? 

55) A 600N woman
stands on top of a very tall ladder so she is one Earth radius above Earth’s
surface. How much does she weigh? 

56) Suppose the
gravitational force between two masses is 20 N. If the volume of each mass doubles,
while everything else stays the same, what is the force between the masses? 

57) Why is it
that it is so difficult to detect gravitational forces between ordinary
objects? 

58) A very
massive object A and a less massive object B move toward each other under the
influence of mutual gravitation. Which is greater, the force on A, or the
force on B? 

59) According
to 

60) Each of us
weighs a tiny bit less on the ground floor of a skyscraper than we do on the
top floor. One reason for this is that ___________ 

61) What did 

62) Two objects
move toward each other because of gravitational attraction. As the objects
get closer and closer, what happens to the force between them? 

63) Why doesn’t
the moon fall into the Earth? 

64) If the mass
of Earth increased, with no change in radius, what would happen to your
weight? 

65) 

66) Jupiter has
more than 300 times the mass of Earth. Yet on Jupiter’s surface an object weighs
only about 3 times as much as it would on Earth. Why is this? 

67) A hollow
spherical planet is inhabited by people who live inside it, where the
gravitational field is zero. When a very massive space ship lands on the
planet’s surface, how does the gravitational field change within the planet?
Why? 

68) A lunar
month is about 28 days. If the moon were closer to Earth than it is now, what
would happen to the lunar month? 

69) A supplier wants
to make a profit by buying metal by weight at one altitude and selling it at
the same price per pound at another altitude. Where should the supplier buy
and where should he sell? Would altitude have a significant effect? 

70) If Earth’s
mass decreased to one half its original mass, with no change in radius, what
would happen to your weight? 

71) Suppose the
gravitational force between two massive spheres is 20 N. If the distance between
the spheres is cut in half, what is the force between the masses? 

72) 

73) By noticing
that Uranus’s orbit is perturbed and by using the law of gravitation, two
astronomers independently discovered ____________ 

74) If you
stood atop a ladder on Earth that was as tall as Earths radius (so you were twice
as far from Earth’s center) what would happen to your weight atop the ladder? 

75) Consider
the gravitational force between the earth and a meteor in outer space. If the
meteor moves so its distance from the earth’s center doubles, what happens to
the gravitational force on the meteor? The gravitational force on the earth? 

76) If the radius
of Earth decreased, with no change in mass, what would happen to your weight? 

77) Is the
force of gravity on you greatest when you are standing on the earth’s
surface, slightly above the earth’s surface, or slightly below the earth’s
surface? Why? 

78) If you
burrow deeply into a planet what will happen to the force of gravity on you?
What will happen if the planet’s radius simply shrinks with you remaining on
the surface? 

79) Compare the
gravitational force between Earth and Mars, and the gravitational force
between a newborn baby and the doctor who holds it. The greater force is
between ___________ 

80) Which is
greater, the gravitational force between Earth and the moon, or between Earth
and the sun? 

TRUE/FALSE.
If true, mark “A”, if false; mark “B” on the Scantron 
T/F 
81)
What are the two possible outcomes of the expansion of the universe? 
T
 F 
82)
Because Earth and moon are gravitationally attracted towards each other, will
they soon collide? Explain. 
T
 F 
83)
Does the force on a ball decreases as the ball moves farther from Earth?
Explain in terms of 
T
 F 
84)
If Earth were to disappear, would the moon still orbit the place where Earth
was? Explain why or why not. 
T
 F 
85)
What is the name of the component of an orbiting satellite’s velocity that is
parallel to Earth’s surface? 
T
 F 
86)
The force of attraction between two masses depends inversely on the square of
the distance between the masses. What is the name for any law that has this
kind of dependence on distance? 
T
 F 
87)
If Earth were its present size but twice as massive, what would happen to our
weight? 
T
 F 
88)
Is there is a force on Earth that is directed toward the sun? 
T
 F 
89)
Because Earth is “falling” around the sun, will it eventually fall into the
sun? Why or why not? 
T
 F 