You stand on a frictional platform that is rotating at 1.4 rev/s. Your arms are outstretched, and youhold a heavy weight in each hand. The moment of inertia of you, theextended weights, and the platform is 8.6 kg · m2. When you pull theweights in toward your body, the moment of inertia decreases to4.4 kg · m2.
(a) What is the resulting angular speed of theplatform?
(b) What is the change in kinetic energy of the system?
(c) Where did this increase in energy comefrom?