1. Newton hypothesized that the moon: a) is a projectile b) is actually attracted to Earth c) is falling around Earth d) 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

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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) one quarter b) half c) double d) 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) 40 N b) 20 N c) 10 N d) 5 N e) 2.5 N

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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) depends on the radius of Earth b) depends on the mass of Earth c) depends on the universal gravitational constant d) is different on different planets e) all of the above

12.Gravitational field lines show the: a) direction a mass would be accelerated b) direction of the field c) direction of the force on any mass d) strength of the field e) all of the above

13.The acceleration due to gravity at the center of the earth is: a) large b) the same as on the surface c) slightly less than on the surface d) zero

14.If you were to weigh yourself in an elevator that is accelerating upward, compared to your ordinary weight you would weigh: a) more b) the same c) less, but more than zero d) 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) Earth is orbiting so fast b) Earth is rotating so fast c) the sun is so far away d) the sun is radiating a lot of energy e) 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) size b) mass c) color d) not even light can escape e) none of the above