The 12-lb uniform disk shown, of radius r = 3.2 in., rotates counterclockwise. Its center...

The 12-lb uniform disk shown, of radius r = 3.2 in., rotates counterclockwise. Its center C is constrained to move in a slot cut in the vertical member AB and an 11-lb horizontal force P is applied at B to maintain contact at D between the disk and the vertical wall. The disk moves downward under the influence of gravity and the friction at D. Knowing that the coefficient of kinetic friction between the disk and the wall is 0.12 and neglecting friction in the vertical slot, determine (a) the angular acceleration of the disk, (b) the acceleration of the center C of the disk.

Fig. P16.55