For the instant represented when $y=160mm,$ the

piston rod of the hydraulic cylinder $C$ imparts a ver$-$

tical motion to the pin $B$ consisting of $y^{}=400m\frac{m}{s}$

and $y^{}=-100m\frac{m}{s^2}.$ For this instant determine the

angular velocity $$ and the angular acceleration $$ of

link $OA.$ Members $OA$ and $AB$ make equal angles

with the horizontal at this instant.