Question

Find the speed of a car in miles per hour, if its wheels, that have a diameter of 18 inches, travel at a rate of 10 revolutions per second.

Answer 1

Explanation:

circumference=πd=π×18=18π in

distance covered in 1 sec=18π×10=180π in.

distance covered in 1 min=180π×60=10800π in

distance covered in 60 min=10800π×60=648000π in=648000π÷12=54000π ft

=54000π÷3=18000π yards=18000π÷1760≈32.13 miles per hour.