Question

A roller of diameter $0.9m$ and length $1.8m$ is use to press the ground. Find the area of the ground in $500$ revolutions.

Answer 1

The roller is a cylinder $\left(d\right)=0.9m$

$r=\frac{0.9}{2}m$

$l=1.8m=h$

C.S.A of a cylinder $=2\pi rh$

$\begin{array}{c}=2\times \frac{22}{7}\times \frac{0.9}{2}\times 1.8\\ =5.0914m^2\end{array}$

Area of the ground pressed by it in one Revolution $=5.0914m^2$

in 500 Revolution $=500\times 5.0914$

$=2545.7m^2$