A student sits on a rotating stool holding two weights, each of mass 3.00 kg. When his arms are extended horizontally, the weights are 0.700 m from the axis of rotation and he rotates with an angular speed of 0.850 rad/s. The moment of inertia of the student plus stool is 3.00 kg·m2 and is assumed to be constant. The student pulls the weights horizontally to 0.300 m from the rotation axis.
(a) Find the new angular speed of the student.
(b) Find the kinetic energy of the student before the weights are pulled in. Find the kinetic energy of the student after the weights are pulled in.