Question

Suppose a fast-pitch softball player does a windmill pitch, moving her hand through a circular arc with her arm straight. She releases the ball at a speed of 18.3 m/s (about 40.9 mph). Just before the ball leaves her hand, the ball's radial acceleration is 730 m/s2. What is the length of her arm from the pivot point at her shoulder?

Answer 1

Radial acceleration of the object in circular motion is given by formula

$a = \frac{v^2}{R}$

$a = 730 m/s^2$

$v = 18.3 m/s$

now by the formula

$730 = \frac{18.3^2}{R}$

$R = 0.46 m$

so length of his arm is 46 cm