$9\mathrm{.}1.$ The link lengths and the values of ${}_2,{}_2,$ and $$ for some inverted four bar crank$-$slider linkages are defined. Find the angular acceleration of link $4$ and acceleration of slip at the sliding joint; crossed configuration only.

Link lengths:

Link $2a$:$=2*in,$ Link $4,c$:$=4*$ in Link $1,d$:$=6*in$

Angle between links $3$ and $4,$:$=90*deg$

Link $2$ position, velocity, and accel. $,{}_2$:$=30*deg,{}_2$:$=10*\frac{\text{r}\text{a}\text{d}}{sec},{}_2$:$=-25*\frac{\text{r}\text{a}\text{d}}{se{c}^2}$