700 rotations If the radius is 1 foot, the diameter is 2 feet (twice the radius). The circumference of a circle is pi times the radius. Using 22/7 as pi, the circumference of each tire is (22/7)*2 feet. That is the same as 44/7 feet. If the car is going 4400 feet per minute, the tires will "rotate 4400 feet from the circumference" - if you know what I mean. The tire completes one rotation every 44/7 feet. So, in 4400 feet it will complete (4400)/(44/7) feet. That is equal to 4400*7/44. Put that in a calculator and you get: 700. **
