How many revolutions will a car wheel of diameter 18 in. make as the car travels a distance of one mile? (Round your answer to the nearest whole number.)
The radius is 9in = 3/4 ft
The distance that the whell travels in one revolution is 2pi * (3/4) ft = (3/2)pi ft = (1.5pi ) ft
The number of feet in a mile = 5280
So....the number of revolutions it makes is
5280 /[ 1.5pi ] ≈ 1120 revolutions
