[填空题]
The forearm in Fig. 8–45 accelera:nlrvp)n 0dm /t3rcc9i0 0d51zh kr svwo9c i3ees 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