[填空题]
The forearm in Fig. 1vvv k5(np 6bqu: kk4r 7r9yjt8–45 accsgvmj.j8/pk)k hwb/ /elerates a 3.6-kg ball at 7 $m/s^2$ by means of the triceps muscle, as shown. Calculate (a) the torque needed, $m \cdot N$ (b) the force that must be exerted by the triceps muscle. Ignore the mass of the arm. N