A bicycle wheel has a diameter of 2 feet and turns at the rate of 70 revolutions per minute. How fast does the wheel move in feet per hour?

Answer 1

One rotation is π(diameter) = 2π ft
so in one minute it goes 70(2π) = 140π) ft
in one hour it goes 60(140π) ft
= 8400π ft/hr

or appr 26389 ft/hr