Question

A student sits at rest on a piano stool that can rotate without friction. The moment of inertia of the student-stool system is 4.6 kg m^2. A second student tosses a 1.5 kg mass with a speed of 2.9 m/s to the student on the stool, who catches it at a distance of 0.40 s from the axis of rotation. what is the initial and final kinetic engergy