[填空题]
The forearm in Fig. 8–45 acceler jgca4y;gqr(h73vgi 0fids05akw 1r .(rtoze gm68xl0tes 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