Unit Test Review – Forces, Gravitation, and Kepler’s Laws

You are sitting next to your favorite pet. If you are 50.0kg and your pet is 10.0 kg, and your center
of masses are 0.50m apart, then what is the scientific "force of attraction" between you and your
favorite pet? *Solve this problem for the gravitational force between you and your pet.

𝐹𝑔 = 𝐺𝑚1𝑚2
𝑑2 = 6.67𝑥10 ―11𝑁 ∙ 𝑚2/𝑘𝑔2(50.0𝑘𝑔 )(10.0𝑘𝑔)
(0.5𝑚)2 =

What is the distance between two asteroids 1.0 x 1012 kg and 5 x 1012 kg respectively if the force of
attraction between them is 10.00 N?

10 𝑁 = 6.67𝑥10 ―11𝑁 ∙ 𝑚2/𝑘𝑔2(1.00𝑥1012𝑘𝑔 )(5.0𝑥1012𝑘𝑔)
(𝑑)2
(𝑑)2 = 6.67𝑥10 ―11𝑁 ∙ 𝑚2/𝑘𝑔2(1.00𝑥1012𝑘𝑔 )(5.0𝑥1012𝑘𝑔)
10𝑁
(𝑑)2 = 6.67𝑥10 ―11𝑁 ∙ 𝑚2/𝑘𝑔2(1.00𝑥1012𝑘𝑔 )(5.0𝑥1012𝑘𝑔)
10𝑁
𝑑 = 5774945.887 𝑚 ---------> round to 2 sig figs ---------> 5.8x106 m
3. Jupiter’s mean orbital radius is 5.2025 AU’s. What is Jupiter’s period in Earth years?
Answer:

Jupiter’s mean orbital radius is 5.2025 AU’s. What is Jupiter’s period in Earth years?

The planet Mercury takes 0.24 years to go around the Sun. What is the average distance from the
center of Mercury to the center of the Sun?
Answer:

Because the earth and moon are gravitationally attracted towards each other, they will soon collide

false

The gravitational force of the earth on an object decreases as the object moves farther from the earth.

true