1. The problem statement, all variables and given/known data I'm given a chart that states the r average and T in earth days for the moons of Uranus and I have to find the Kepler's constant for the last four moons, which only gives me either the radius or period.. I am confused. How can I find K with only r or T? I need at least the mass of Uranus yes? 3. The attempt at a solution Am I suppose to find out the mass of Uranus myself somehow?