[填空题]
The forearm in Fig. 8–45 ac2wbm5ms a r2w)celerates a 3.6-kg ball gt n:toq5 n/ 1l,d sw6.xgpjl5at 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