${?}^{}3\mathrm{.}17$ For the modified slider$-$crank linkage in the posture shown, crank $2$ has an angular velocity of $10ra\frac{d}{s}ccw.$ Find the angular velocity of link $6$ and the velocities of points $B,C,$ and $D.$

Figure P$3\mathrm{.}17R_{A{O}_2}=2\mathrm{.}5in,R_{BA}=10in,R_{CB}=8in,R_{CA}=R_{DC}=4in,R_{O_6{O}_2}=8in,$ and $R_{D{O}_6}=6$ in$.$