[填空题]
The forearm in Fig. 8–45 anlj 1z)uqo9 n jla(*(2sif ke4ccelerd*fdurwn;jd5*x0;ihau68j,cbyf 4) h m ,omt ates 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