A horizontal circular platform (M = 73.1 kg, r = 3.07 m) rotates about a frictionless vertical axle. A 93.3 kg student walks slowly from the rim of the platform toward the center. The angular velocity of the system is 3.9 rad/s when the student is at the rim. Discover the angular velocity of the system when the student is 1.37 m from the center.