[填空题]
Assume that a 1.00-kg balvb6:fb8llv or-d n;dv/ wr f:6l is thrown solely4o ,l+n)eum eh by the action of the forearm, which rotates about the elbow joint under the action of the triceps muscle, luo 4)he+,nm eFig. 8–45. The ball is accelerated uniformly from rest to 10 $m/s$ in 0.350 s, at which point it is released. Calculate (a) the angular acceleration of the arm, $rad/s^2$ (b) the force required of the triceps muscle. Assume that the forearm has a mass of 3.70 kg and rotates like a uniform rod about an axis at its end. N