Problem $12\mathrm{.}72$

A $700-$kg horse A lifts a $50-$kg hay bale $B$ as shown. At the instant when $r=8m$ and $=60,$ the

velocity and acceleration of the horse are $2\frac{m}{s}$ to the right and $0\mathrm{.}5\frac{m}{s^2}$ to the left, respectively.

Neglecting the mass of the pulley, determine at that instant $(a)$ the tension in the cable, $($b$)$ the average

horizontal force between the ground and the horse's feet.

Fig. P$12\mathrm{.}72$