A student sits on a freely rotating stool holding two weights, each of which has a mass of 2.31kg. When his arms are extended horizontally, the weights are 1.020m from the axis of rotation and he rotates with an angular speed of 0.628rad/s. The moment of inertia of the student plus stool is 2.00kgm^2 and is assumed to be constant. The student pulls the weights inward horizontally to a position 0.300m from the rotation axis.
A) Find the new angular speed of the student.
B) Calculate the kinetic energy of the system before the student pulls his arms inwards.
C) Calculate the final kinetic energy of the system