It is 60 feet 6 inches from the pitcher's mound to home plate. How long does it take for a pitch to travel from the time it leaves the pitcher's hand to home plate if the pitcher throws a fastball 90 miles per hour? Assume the pitch leaves his hand directly over the pitching rubber even though, in reality, it leaves closer to home plate.

Solution

We will use the formula d = r t and the following conversion facts:

1 mile = 5,280 feet

1 hour = 60 minutes

1 hour = 3,600 seconds (60 x 60)

1 minute = 60 seconds

d = r t

60.5 ft = 90 miles t

hour

60. 5 ft = 90 miles x 5280 ft x t

hour mile

60. 5 ft = 90 miles x 5280 ft x t (we convert miles to feet)

hour mile

60. 5 ft = 90 x 5280 ft x t

hour

60. 5 ft = 90 x 5280 ft x 1 hour t (we convert to seconds)

hour 3600 seconds

60. 5 ft = 90 x 5280 ft x t (we convert to seconds)

3600 seconds

60.5 ft = 132 ft x t

second

60.5 ft = 132 ft/sec x t (we divide each side of the equation

132 ft/sec 132 ft/sec by 132 ft/sec)

60.5 ft = 132 ft/sec x t

132 ft/sec 132 ft/sec

60.5 ft = t = .483 seconds

132 ft/sec