Question

The diameter of a car wheel is 60 cm, if the car travels at an average speed of 13.2m/s, find the number of revolutions made by the car per hour , hiving the awnser correct to nearest whole number. (take pie to be 3.142 )

Answer 1

The wheel has diameter 60 cm = 0.60 m, and thus circumference π(0.60 m) ≈ 5.923 m.

In one complete revolution, a point on the edge of the wheel covers this distance, so that the wheel has an angular speed of

(13.2 m/s) * (1/5.923 rev/m) ≈ 2.229 rev/s

There are 60 seconds to each minute, and 60 minutes to each hour, so converting to rev/h gives

(2.229 rev/s) * (60 s/min) * (60 min/h) ≈ 8024 rev/h