Question

1.  Gravity (You shouldn’t need a calculator for these problems)

(a) sum up the universal law of gravitation in words. Then state the law mathematically, explaining the meaning of each symbol in equation.

2.  Understanding Newton’s Version of Kepler’s Third Law

(a) make up another solar system, with a star of the same mass as the Sun. Suppose there is a planet in that solar system with a mass four times that of the Earth, orbiting at a distance of 1 A.U. from the star. What is the orbital period of this planet? Describe, in words, the reason for your answer.

(b) Suppose a solar system has a star that is nine times the mass of our Sun. If that solar system has a planet the same size as Earth orbiting at a distance of 1 A.U., what is the orbital period of the planet? Clarify, in words, the reason for your answer.

3.  Using Newton’s Version of Kepler’s Third Law You will need a calculator for these problems.Answers from Internet won’t do (and may be wrong), you MUST show your work.

Compute orbital period of the International Space Station if it is in a circular orbit 370 kilometers above Earth’s surface. (Does your answer make sense? Remember, satellites in low Earth orbit have periods around 85 minutes. How should your answer compare to these?)