Question

A car has wheels each of which is 84 cm in diameter. Find how many complete revolutions must each wheel take to cover a distance of 792 m.

Answer 1

Let the radius of each wheel be r cm. Then,

Diameter = 84 cm

$2r=84$

$r=42cm$

Thus, circumference of the wheel = $2\pi r$

$2\pi r=2\times \frac{22}{7}\times 42=264cm=2.64m$

Hence, each wheel covers 2.64 m in one complete revolution.

Therefore, total number of revolutions to cover 792 m = $\frac{792}{2.64}=300$.