Newtons Universal Law of Gravity

A 560-N woman stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much does she weigh? a. zero b. 140 N c. 280 N d. 560 N e. none of the above

B

14. The force of gravity on you is greatest when you are standing _____. a. just below Earth's surface b. on Earth's surface c. just above Earth's surface

A

A planet has half the mass of the Earth and half the radius. Compared to its weight on Earth, an apple on this planet would weigh _____. a. twice as much b. one-fourth as much c. half as much d. the same e. zero

A

Newton reasoned that the gravitational attraction between Earth and the moon must be _____. a. reduced by distance b. independent of distance c. directly proportional to distance d. the same at all distances e. all of the above

A

If Earth's mass decreased to one half its original mass, with no change in radius, then your weight would _____. a. stay the same b. decrease to one half your original weight c. decrease to one quarter your original weight d. none of the above

B

If the radius of Earth decreased, with no change in mass, your weight would _____. a. not change b. increase c. decrease

B

If you stood atop a ladder on Earth that was as tall as Earth's radius (so you were twice as far from Earth's center) your weight atop the ladder would be _____. a. one-eighth its normal value b. one-quarter its normal value c. half its normal value d. none of the above

B

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 B b. The force on A c. Both forces are the same.

C

If the mass of Earth increased, with no change in radius, your weight would _____. a. stay the same b. decrease c. increase also

C

The force of gravity on you is greatest when you are standing _____. a. far above Earth's surface b. just above Earth's surface c. on Earth's surface

C

Two objects move toward each other because of gravitational attraction. As the objects get closer and closer, the force between them _____. a. remains constant b. decreases c. increases

C

The gravitational force between two massive spheres a. is always an attraction. b. depends on how massive they are. c. depends inversely on the square of the distances between them. d. all of the above

D

Suppose the gravitational force between two massive spheres is 100 N. If the distance between the spheres is doubled, what is the force between the masses? a. 400 N b. 200 N c. 100 N d. 50 N e. 25 N

E

Suppose the gravitational force between two spheres is 30 N. If the magnitude of each mass doubles, what is the force between the masses? a. 8 N b. 15 N c. 30 N d. 60 N e. 120 N

E