Question

The diameter of a garden roller is $1.4$m and $2$m long. How much area will it cover in $5$ revolutions?

Answer 1

We know that the curved surface area of a right circular cylinder with radius $r$ and height $h$ is $CSA=2\pi rh$.

It is given that the height of the garden roller is $h=2$ m and the diameter of the garden roller is $1.4$ m, and therefore the radius of the roller is $\frac{1.4}{2}=0.7$ m, therefore,

$CSA=2\pi rh=2\times \frac{22}{7}\times 0.7\times 2=8.8$m${}^2$

Therefore, the curved surface area is $8.8$ m${}^2$.

And, the area of the garden covered by the roller in $5$ revolutions is:

$8.8\times 5=44$m${}^2$

Hence, it will cover the area of $44$m${}^2$ in $5$ revolutions.