1. The problem statement, all variables and given/known data When a moon orbits a planet, it can be shown that the period of the moon's orbit depends only on the mass of the planet and the radius of the moon's orbit. a) Draw and label a diagram to illustrate the variables. b) Derive a formula for the period of a moon's orbit. The only variables in the final answer should be the mass of the planet and the radius of the orbit. All other values should be constants. 2. Relevant equations Fg= Gm1m2/r^2 g=Gm1/r^2 3. The attempt at a solution Okay, I don't really understand how to make formula's to get an answer like this. I figure that the variables in the formula would be the period of orbit, mass and radius. The constants would probably be pi and G. Could someone give me a hint at how to do this?