Space Objects
Fg=...
Forceful Words
Double Jeopardy
100

An object is placed exactly halfway between Earth and the moon. The object will fall toward __________ . a. the moon b. Earth c. neither Earth nor the moon

B. the Earth!

100

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

C. Increase!

100

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. The gravitational force is an attractive force that depends on the mass of two objects AND on the distance between them (squared)!

100
A circle is a special case of this shape, which describes the orbital path of ALL satellites - not just those which travel in circles.
What is an ellipse?
200
Newton hypothesized that the moon _________. a. is a projectile b. is falling around Earth c. is actually attracted to Earth d. all of the above
D. The moon is a projectile which is attracted toward Earth and is falling around the Earth!
200
If the radius of Earth decreased, with no change in mass, your weight would _______ . a. not change b. increase c. decrease
B. Increase!
200
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 of A on B b. The force of B on A c. Both forces are the same
C. By Newton's Third Law, both forces are the same!
300
Newton reasoned that the gravitational attraction between the Earth and the moon must be __________ . a. reduced by distance b. independent of distance c. indirectly proportional to distance d. the same at all distances
A. Reduced by distance!
300
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. Decrease to one half your original weight!
300
The force of gravity on you is greatest when you are standing: a. far above the Earth's surface b. just above the Earth's surface c. on the Earth's surface
C. On the earth's surface!
400
The reason the moon does not fall into Earth is that ______. a. Earth's gravitational field at the moon is weak b. the moon has a sufficiently large orbital speed c. the gravitational pull of other planets keeps the moon up d. the moon has less mass than Earth
B. Its orbital speed is large enough!
400
Two objects move toward one another because of gravitational attraction. As the objects get closer and closer, the force between them _________ . a. remains constant b. decreases c. increases
C. Increases!
400
Each of us weighs a tiny bit LESS on the ground floor of a skyscraper than we do on the top floor. This is because ___. a. the gravitational field is shielded inside the building b. the mass of the building attracts you upward slightly c. both A and B d. neither A nor B
B. The mass of the building attracts you upward slightly!
500
Since Earth is attracted to the sun, why doesn't it fall into the sun? a. It has too much mass to move toward the sun. b. It has a sufficiently large orbital velocity. c. There is an equal force holding it away from the sun. d. It has too much inertia to move toward the sun.
B. Its orbital velocity is large enough!
500
Suppose the gravitational force between two massive spheres is 100 N. If the distance between the spheres is doubled, what is the force between them? a. 400 N b. 200 N c. 100 N d. 50 N e. 25 N
E. 25 N!
500
When in orbit, a satellite such as the space shuttle is: a. a projectile under the force of Earth's gravity b. experiencing non-acclerated motion b. free from Earth's gravity
A. Satellites are projectiles under the force of Earth's gravity!
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