The quarter$-$circular link $AB$ with small rollers at two ends has a radius of $0\mathrm{.}8$ m $($that is$,$ it is part of a circle of radius $0\mathrm{.}8$ m $).$ At the instant shown, roller A has a speed $v_A=2\frac{m}{s}$ to the right and roller $B$ moves along the incline of angle $=70$ with the horizontal. Calculate the angular velocity of the link and the speed of point $B$ on the link for this instant. $\frac{m}{s})$