Problem $16\mathrm{.}131!$

Disk $D$ rolls without slipping over the horizontal surface. At the instant shown, point $A$ on $\frac{?}{\text{b}\text{a}\text{r}}OA,$ which is pinned to the fixed point at $O$ at its left end, is moving straight down

with constant speed $v_0.$ End $B$ of bar $AB$ is pinned to the disk at point $B.$ At this instant, determine, as functions of $R$ and $v_0,$ the angular velocities and angular accelerations of bar $AB$ and disk $D.$