[填空题]
The forearm in Fig. 8–45 ac(kc3mmcc ,q4 c0*co kvcex50gx6n.xkzp rgl b)8lerates 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