If you are going to answer, please show the work. I know the answer, I need to u

Question

If you are going to answer, please show the work. I know the answer, I need to understand the process!

A softball pitcher throws with the arm fully extended; the arm is straight at the elbow. The pitch leaves his hand at a speed of 139 km/h. First, find the rotational kinetic energy of the pitcher's arm given its moment of inertia is 0.720 kg.m^2 and the ball leaves the hand at a distance of 0.600 m from the pivot at the shoulder. Next, what force did the muscles exert to cause the arm to rotate if their effective perpendicular lever arm is 4.00 cm and the ball is 0.156kg?

Explanation / Answer

rotational KE = 0.5 Iw^2

rot KE = 0.5 * 0.720* (0.6*139*5/80)^2

rot KE = 193.21 J

b. torque T = I* alpha

F* 0.04 = 0.72 * 0.198

F = 3.58 N

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