A car is traveling at a speed of 50 miles per hour. Each wheel of the car makes 770 revolutions per minute. To the nearest tenth of an inch, what is the diameter of each car wheel? (Note: 1 mile = 5,280 feet)

Answer: 21.8 inches

Given:

A car is traveling at a speed of 50 miles per hour. Each wheel of the car makes 770 revolutions per minute.

To get the diameter of each car wheel

Get first the length of revolution (circumference of the wheel) in inches.

Speed=50 miles/hr

=50miles/60 minutes

= 0.833333 miles/minute

=.833/5280=4400ft = 52,800 inches/minute

Since there are 770 revolutions per minute, per revolution (circumference of the wheel) =

=52,800/770

=68.57 inches

Formula of diameter given the circumference is:

D=C/π

D=68.57/3.14

D = 21.8 inches