A horizontal circular platform (M = 122.1 kg, r = 3.17 m) rotates about a frictionless vertical axle. A 56.3 kg student walks slowly from the rim of the platform toward the center. The angular velocity of the system is 3.3 rad/s when the student is at the rim. Find the angular velocity of the system when the student is 1.65 m from the center.


Remember to conserve angular momentum of the system both before and after the student moves.