A disk of mass M is spinning freely at 9.67 rad/s when a second identical disk, initially not spinning, is dropped onto it so that their axes coincide. In a short time the two disks are corotating. (a) What is the angular speed of the new system (in rad/s)? rad/s (b) If a third such disk is dropped on the first two, find the final angular speed of the system (in rad/s). rad/s