Download Test Review Sheet

Test Review Sheet
‘Gravitational force’
There will be a TEST next class(B day; 5/2 or A day; 5/5).
‘Gravitational InteractionI, II’ and ‘Practice QuestionVIII’
The test will be based on
True or False
1. If Earth had its present mass but twice the radius, the acceleration due to gravity would
increase
(True False)
2. The Sun pulls harder on Earth’s ocean than the moon (True False)
3. Ocean tides are caused by differences in the gravitational pull between the moon and the
opposite sides of Earth (True False)
4. If the distance between two objects doubles, then the gravitational force acting between them
would be one half the original force (True False)
Multiple Choice
1. Two objects move toward each other because of gravitational interaction. As the objects gets
closer and closer, the force between them
a) increase
b) decrease
c) remain constant
d) increase and then decrease
2. Suppose the gravitational force between two massive spheres is 10N. If the distance between
them the spheres is cut in half, what is the force between the masses?
a) 40N
b) 20N
c) 10N
d) 5N
e) 2.5N
3. 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
4. The factor most directly responsible for making a black hole invisible is its
a) size
b) mass
c) color
d) escape velocity
5. Two friends say they cannot feel the gravitational attraction between them. The reason for that
is because
a) gravitational force does not exist between living things
b) the friend’s masses are too small for the gravitational force between them to be significant
c) gravity only acts at large distance; they are too close together
d) there is too much friction between their chairs and the floor
6. The mass of an object at the surface of the Earth compared to the mass of the same object at a
distance of two Earth radii from the surface of the Earth is:
a) the same
b) one half
c) one quarter
d) one ninth
7. Which of the following graphs best represents the gravitational force between two masses as
the distance between the masses change is:
a)
Fg
b)
Fg
r
c)
Fg
r
d)
Fg
r
r
8. A 90kg astronaut weighs 1/6 as much on the moon as on Earth because:
a) the moon is made of denser rock than the Earth
b) the astronaut is closer to the center of the mass when standing on the moon’s surface
c) the mass of the Earth also pulls on the astronaut
d) the mass of the moon is substantially less than the mass of the Earth
9. If the distance between two objects were doubled, the force of gravitational attraction between
the object would be:
a) the same
b) double the original force
c) one half the original force
d) one quarter the original force
10. The force of gravitational attraction between two objects is 20N. If the mass of one of the
object were doubled, the gravitational force between the objects would be:
a) 5.0N
b) 10N
c) 40N
d) 80N
11. The force of gravitational attraction between two objects is 20N. If the mass of both objects
were doubled, the gravitational force between the objects would be:
a) 5.0N
b) 10N
c) 40N
d) 80N
12. Two stars are bound together by gravity. The larger star has four times the mass of the smaller
star. Which diagram best illustrates the orbital motion of the two stars?
a)
b)
c)
d)