Two disks have equal masses, m, and radii, R. Their moments of inertia are each .5mR^2. The upper disk can rotate freely around a horizontal axis through its center, but is attached to a surface, so that it doesn't move up or down. A rope is wrapped around both disks, and the lower one is permitted to fall. Find:

(a) the acceleration of the center of mass of the lower disk,

(b) the tension in the rope, and

(c) the angular acceleration of each disk around its center of mass.