AP 1 PSI Physics Name: ___________________
Gravitation Test v1 Date:________________
Multiple Choice Section
1. A hypothetical planet orbits a star with mass 4 times the mass of our sun. The planet’s orbital
radius is the same as the Earth’s. Approximately how many Earth years does it take for the
planet to complete one orbit?
(A) 1
2 (B) 1
√2 (C) 1 (D) √2
2. As a rocket moves away from the Earth’s surface, the rocket’s weight
(A) increases. (B) decreases. (C) remains the same.
(D) depends on how fast it is moving.
3. Two artificial satellites, 1 and 2, are put into circular orbit at the same altitude above Earth’s
surface. The mass of satellite 2 is half the mass of satellite 1. If the period of satellite 1 is T,
what is the period of satellite 2?
(A) T/2 (B) T (C) 2T (D) 4T
4. A satellite encircles Mars at a distance above its surface equal to 3 times the radius of Mars.
The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the
surface of Mars, is
(A) zero. (B) the same. (C) one–ninth as much. (D) one–sixteenth as much.
5. A planet has a radius twice that of Earth and a ten times the Earth’s mass. The gravitational
acceleration at the surface of the planet is most nearly
(A) 4.0 m/s2 (B) 8.0 m/s2 (C) 12.5 m/s2 (D) 25 m/s2
6. In the following problem, the word “weight” refers to the force a scale registers. If the Earth
were to increase its rotating speed, but not change shape,
(A) the weight of an object at the equator would increase.
(B) the weight of an object at the equator would decrease.
(C) the weight of an object at the North Pole would increase.
(D) the weight of an object at the North Pole would decrease.
7. The radius of Earth is R. At what distance above Earth’s surface will the acceleration of gravity
be 2.45 m/s2?
(A) 0.41 R (B) 1.0 R (C) 1.41 R (D) 2R
8. What happens to the force of gravitational attraction between two small objects if the
distance between their centers is halved?
(A) It is doubled (B) It is quadrupled (C) It is halved (D) It is reduced fourfold
9. Two planets have the same surface gravity, but planet B has twice the mass of planet A. If
planet A has radius r, what is the radius of planet B?
(A) 0.707r
(B) r
(C) 1.41r
(D) 4r
10. Two spheres, with radii of R, are in contact with each other and attract each other with a force
of F. If the radii of both of the spheres are cut to half while the density remains the same,
what is the new gravitational force between them?
(A) 16F (B) 4F (C) F/2 (D) F/16
