A circular disk of radius 25.0cm and rotational inertia 0.015kg.m2 is rotating freely at 22.0 rpm with a mouse of mass 21.0g at a distance of 12.0cm from the center. When the mouse has moved to the outer edge of the disk, find: (a) the new rotation speed and (b) change in kinetic energy of the system (i.e disk plus mouse). (6 pts)