[填空题]
The forearm in Fig. 8–45 accele+h-b gu0t*ozwq .xt u(rates zp6nml.tw k 51+1dbk qko1 l:ja 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