Transcript Universal Gravitation

1. Newton hypothesized that the moon:
a)
b)
c)
d)
is a projectile
is actually attracted to Earth
is falling around Earth
has tangential velocity that prevents it from
falling into earth
e) all of the above
2. If the radius of Earth decreased, with no
change in mass, your weight would:
a) increase
b) not change
c) decrease
m1m2
F G 2
r
3. A very massive object A and a less massive
object B move toward each other under the
influence of mutual gravitation. Which force,
if either, is greater?
a) the force on A
b) the force on B
c) both forces are the same
4. A very massive object A and a less massive
object B move toward each other under the
influence of mutual gravitation. Which
object will accelerate more?
a) object A
b) object B
c) both objects accelerate the same
5. The force of gravity on you is greatest when
you are standing:
a) above the earth’s surface
b) at the center of the earth
c) on the earth’s surface
6. 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, the gravitational force
on the meteor will be:
a)
b)
c)
d)
one quarter
half
double
quadruple
7. Why did Newton think there was a force
acting on the moon?
a) because the moon always keeps one side toward
Earth
b) because the moon moves in a curved path
c) because there is no air on the moon
d) because the moon is moving
e) all of the above
8. Suppose the gravitational force between two
masses is 10 newtons. If the volume of each
mass doubles, while everything else stays the
same, what is the force between the masses?
a)
b)
c)
d)
e)
40 N
20 N
10 N
5N
2.5 N
m1m2
F G 2
r
9. The force of attraction between two masses
depends inversely on the square of the
distance between them. Any law that follows
this relationship is called an inverse square
law.
a) true
b) false
10.Because Earth is “falling” around the sun, it
will eventually crash into it.
a) true
b) false
11.The value of the acceleration due to gravity:
a)
b)
c)
d)
e)
depends on the radius of Earth
depends on the mass of Earth
depends on the universal gravitational constant
is different on different planets
all of the above
12.Gravitational field lines show the:
a)
b)
c)
d)
e)
direction a mass would be accelerated
direction of the field
direction of the force on any mass
strength of the field
all of the above
13.The acceleration due to gravity at the center
of the earth is:
a)
b)
c)
d)
large
the same as on the surface
slightly less than on the surface
zero
14.If you were to weigh yourself in an elevator
that is accelerating upward, compared to
your ordinary weight you would weigh:
a)
b)
c)
d)
more
the same
less, but more than zero
zero
15.The affect of the sun’s pull on the earth’s
oceans is much less visible that that of the
moon’s pull because:
a)
b)
c)
d)
e)
Earth is orbiting so fast
Earth is rotating so fast
the sun is so far away
the sun is radiating a lot of energy
none of the above
16.A lunar eclipse occurs when:
a) the sun is between Earth and the moon
b) the moon is between Earth and the sun
c) Earth is between the moon and the sun
17.When a star collapses to form a black hole,
its mass:
a) undergoes an enormous increase
b) decreases
c) remains the same
18.The factor most directly responsible for
making a black hole invisible is:
a)
b)
c)
d)
e)
size
mass
color
not even light can escape
none of the above