A student sits on a freely rotating stool holding two weights, each of mass 3.09 kg. When his arms are extended horizontally, the weights are 1.08 m from the axis of rotation and he rotates with an angular speed of 0.753 rad/s. The moment of inertia of the student plus stool is 3.09 kg·m2 and is assumed to be constant. The student pulls the weights in horizontally to a position 0.302 m from the rotation axis.
(a) Find the new angular speed of the student.
(b) Find the kinetic energy of the student before and after he pulls the weights inward.