Question

A pick-up truck is fitted with new tires which have a diameter of 43 inches. How fast will the pick-up truck be moving when the wheels are rotating at 400 revolutions per minute? Express the answer in miles per hour. (mph)

Answer 1

v = 51.19 mph

Explanation:

The diameter of the tires, d = 43 inches

The angular velocity of the wheels = 400 revolutions per minute

400 revolutions per minute = (400/60) rev/s = 6.67 rev/s

The circumference of the tire is :

C = 2πr

= 2π×21.5

= 135.08 inches

The speed of the truck is given by :

`v=6.67 * 135.08 \\\\v=900.983\ in/s`

or

v = 51.19 mph

So, the speed of the truck is equal to 51.19 mph.