Posted by Jackie on .
A horizontal circular platform (m = 108.1 kg, r = 3.25m) rotates about a frictionless vertical axle. A student (m = 85.3kg) walks slowly from the rim of the platform toward the center. The angular velocity, omega, of the system is 2.5 rad/s when the student is at the rim. Find omega when the student is 2.29m from the center.

physics 
bobpursley,
moment of inertia is the sum of the platform and the student (mr^2).
I1*w1=I2*w2