[填空题]
The forearm in Fig. + vgpr. p0c9k f64xriqsnymibt0:v(6 shh qhi)z4h7 98–45 accelerates 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