[填空题]
The forearm in Fig. 8–45 acceleratesv(nj;acyahi4*k uec ) 5ur7a* a 397jouz1f)k( af zcuvq 2w.vn0.6-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