In a softball windmill pitch, the pitcher rotates her arm through just over half a circle, bringing the ball from a point above her shoulder and slightly forward to a release point below her shoulder and slightly forward. Figure P7.16 shows smoothed data for the angular velocity of the upper arm of a college softball pitcher doing a windmill pitch; at time t = 0 her arm is vertical and already in motion. For the first 0.15 s there is a steady increase in speed, leading to a final push with a greater acceleration during the final 0.05 s before the release. During the first 0.15 s of the pitch:

a. What is the angular acceleration?

b. If the ball is 0.60 m from her shoulder, what is the tangential acceleration of the ball? This is the key quantity here—it’s a measure of how much the ball is speeding up. Express your answer in m/s2 and in units of g. c. Through what angle does her arm rotate?

Transcribed Image Text:

Angular velocity (rad/s) 36 24 12 0+ 0 0.05 0.10 0.15 0.20 Time (s) FIGURE P7.16