Question

Assume that a 1.30-kg ball is thrown solely by the action of the forearm, which rotates about the elbow joint under the action of the triceps muscle, the figure. The ball is accelerated uniformly from rest to 8.3 m/s in 0.30 s , at which point it is released. Assume that the forearm has a mass of 3.7 kg and rotates like a uniform rod about an axis at its end.
A) Calculate the angular acceleration of the arm.

B)Calculate the force required of the triceps muscle.

Answer 1

The linear acceleration is, V-Vo 8.3 m/s-0 0.30 s 27.67 m/s The angular acceleration is, 27.67 m/s2 31x10% m = 89.2 rad/s