Question

A road roller makes 200 rotations covering 2200 m. Find the radius of the roller.

Answer 1

Here, one rotation of the road roller is equal to the circumference of the circle.

So, Distance covered in one rotation of the road roller $=\frac{2200m}{200}$ = 11 m

11 m = Circumference of circle $=2\pi r$

Where, r = radius of the road roller

So, $2\times \frac{22}{7}\times r=11m$

$\Rightarrow r=\frac{11\times 7}{2\times 22}=\frac{7}{4}m=1.75m$

So, the radius of the roller = 1.75 m