Question

A car travels 1 kilometre distance in which each wheel makes 450 complete revolutions. Find the radius of its wheels.

Answer 1

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

Circumference of each wheel $=2\pi r=2\times \frac{22}{7}\times rmetres$

Now, distance covered by the wheels in one revolution $=2\times \frac{22}{7}\times rmetres$

$\Rightarrow$ Distance covered by the wheels in 450 revolutions $=2\times \frac{22}{7}\times r\times 450metres$

It is given that the car travels 1 kilometre i.e. 1000 metres distance when its each wheel makes 450 revolutions.

So, $2\times \frac{22}{7}\times r\times 450=1000$

$\Rightarrow r=\frac{7\times 1000}{2\times 22\times 450}=0.3535metres=35.35cm$