1. The problem statement, all variables and given/known data A thin, cylindrical rod = 27.0 cm long with a mass m = 1.20 kg has a ball of diameter d = 10.00 cm and mass M = 2.00 kg attached to one end. The arrangement is originally vertical and stationary, with the ball at the top as shown in the figure below. The combination is free to pivot about the bottom end of the rod after being given a slight nudge. After the combination rotates through 90 degrees, what is its rotational kinetic energy? What is the angular speed of the rod and ball? What is the linear speed of the center of mass of the ball? How does it compare with the speed had the ball fallen freely through the same distance of 32.0 cm? 2. Relevant equations KE = 1/2 I ω^2 v = ωr 3. The attempt at a solution I tried using conservation of energy for the first part but i don't see how if i get mgh = 1/2 I ω^2...where the height is unknown and also i don't understand how to even get I to be quite honest.