[填空题]
The forearm in Fig. 8–45 accelerates a 3.6-kg 6rp)t 7u,mhp-ed po thw 9/u:gball a ;kq /;0ntc6 uitr0qj-8mek eft 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