[填空题]
The forearm in Fig. 8–45 acceleratesqld28m:p /s()dp j yev a 3.6-kg ball at- gey,nv3vfbe*p 0 x* vzwkvwqa3o,28 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