1. The problem statement, all variables and given/known data Two remote planets consist of identical material, but one has a radius twice as large as the other. IF the shortest possible period for a low altitude satellite orbiting the smaller planet is 40 minutes, what is the shortest possible period for a similar low altitude satellite orbiting the larger one? Answer in minutes. 2. Relevant equations volume of sphere=4/3 ∏r3 speed=distance/time Ek=-1/2 Eg 3. The attempt at a solution rB=2rA timeA=2∏r/VA 40=2∏r/VA Don't really know how to move on from here? I know I have to find the time taken for the satellite to orbit planet B. TB=2∏(2rA)/VB I don't know VB, how would I find that?