$14-154*$ A bead B slides along a slot

in a $500-$mm diameter disk that is

rotating about a vertical axis. At

the instant shown, $=3ra\frac{d}{s},{}^{}=8$

$ra\frac{d}{s^2},s=200mm,s^{}=250m\frac{m}{s},$ and

$s^{}=-50m\frac{m}{s^2}.,$ Determine the velocity

vec$(v{)}_B$ and acceleration vec$(a{)}_B$ of the bead at

this instant.