Question: A softball pitcher throws an underhanded pitch with the arm fully extended (straight at the elbow). The ball leaves the pitcher's hand with a speed of 25 m/s. Assume that the pitching motion originates with the arm straight back and terminates with the arm straight down. Do not ignore gravity.
(a) Find the rotational kinetic energy of the pitcher's arm given its moment of inertia is 0.72 kg·m2 and the ball leaves the hand at a distance of 0.550 m from the pivot in the shoulder.
(b) What force did the muscles exert to cause the arm to rotate if their effective perpendicular lever arm was 4.00 cm and the ball had a 0.650 kg mass?