A horizontal platform in the shape of a uniform circular disk rotates on a frictionless bearing about a vertical axle through the center of the disk. The platform has a mass of 150 kg, and radius of 2.00 m. A 60kg student walks slowly from the rim of the platform toward the center. If the angular speed of the system is 1.5 rad/s when the student starts walking, what is the angular speed when she is 0.50 m from the center? I originally used the equation Li=Lf where Li= Iw= (1/2)(MR^2)wi which equals (.5)(210kg)(2.0^2)(1.5rad/s) Li= 630 Lf= (If1+ If2)(wf) =[(.5)(150)(2.0^2) + (60)(0.5^2)]wf This gave me wf= 2.0 rad/s but that doesn't seem to make sense wouldn't the angular speed slow down as the student went closer to the center? Any hints as to where I went wrong is greatly appreciated.