The $12\mathrm{.}5-$Ibf uniform disk shown, of radius $r=3\mathrm{.}1$ in$.,$ rotates counterclockwise. Its center $C$ is constrained to move in a slot cut in the vertical member $AB$ and a $11\mathrm{.}9-$Ibf 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 $D.$ The coefficient of kinetic friction between the disk and the wall is $0\mathrm{.}15$ and neglect friction in the vertical slot. Consider the disk and member $AB$ as separate components, and note that member $AB$ is in static equilibrium while the disk is in general plane motion.

Determine the angular acceleration of the disk at the instant shown in the figure. $=q,k(ra\frac{d}{s^2})$

Determine the acceleration of the center C of the disk at this instant. $a_C=$ i$+|$j$($ft$/$s $($:${?}^2$