[填空题]
The forearm in Fig. 8–40fkwyyfc6m;vr,0 c0 jqiv*s95 accelerates a r.j v3wae,o3h;e mjekf, rq68vx .6md3.6-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