1. The problem statement, all variables and given/known data 2. Relevant equations I have calculated the kinetic energy and the total moment of inertia. https://www.physicsforums.com/file:///C:/Users/javad/AppData/Local/Temp/msohtmlclip1/01/clip_image002.png [Broken] 3. The attempt at a solution I really don't know how to solve the problem. Hope someone can lead me on the right track.