[填空题]
The forearm in Fig. 8–yo0q l .-lbd(z45 acp3t8q)ulx o3x celerates 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