Question

A good baseball pitcher can throw a baseball toward homeplate

at 85mi/h with a spin of 1800rev/min.How many revolutionsdoes the
baseball make on its way to home plate? For simplicity,assume that
the 60 ft path is a straight line.

Answer 1

14.44 revolutions

Step-by-step explanation:

unit conversion:

85mile/hour = 85mile/hour * 5280ft/mile * 1/3600hours/second = 448800ft/hour = 124.67 ft/s

1800rev/min = 1800rev/min * 1/60min/seconds = 30 rev/s

The time it takes for the 85mph base ball to travel 60 ft is

t = s/v = 60 / 124.67 = 0.4813 seconds

By that time, the number of revolution it would make is:

r = 30 * 0.4813 = 14.44 revolutions