A car's wheel (with tire) is 26 inches in diameter and its center is 12 inches above the road. If the car is traveling at 60 feet per second, how fast is the highest point of the tire moving relative to the ground?

Answer 1

The tire must be somewhat flat since the axle is not at the midpoint of the nominal diameter. It is 14 inches from the axle to the top of the tire. The speed of the top of the tire with respect to the axle will be 14/12 = 7/6 of the speed of the bottom of the tire, which is the car's speed.

(7/6) x 60 = 70 ft/s