Answer to Question #20010 in Mechanics | Relativity for jaaz

Question

a good baseball pitcher can throw a baseball towards home plate at 85mi/h with a spin of ball1800rev/min. how revolution does the baseball make on its way to home plate?for simplicity , assume that the60 ft trajectory is a straight line.

Answer 1

First, finding a time it takes to get the baseball to homeplate:
t = S / V, where S is the distance traveled and V is the velocity.
t = 60 ft / 85 mi/h = [1 Mile = 5280 Feet] = 60 / (85 * 5280) =0.00013369 h = 0.0080214 min.
Second, calculating the number of revolutions made: N = t * n = 0.0080214 *
1800 = 14.43852 = approx. 14.5 revolutions.
Answer: 14.5 revolutions.