Question

The diameter of a garden roller is $1.4m$ and it is $2m$ long. How much area will it cover in $50$ revolutions ?

Answer 1

Given diameter of garden roller$=1.4$ m

Radius$=0.7$m

Height$=2$m

The curved surface area of roller$=2\pi rh$

$=2\pi \times 0.7\times 2$

The curved surface area of roller $=2.8\pi m^2$

$\therefore$ In $1$ revolution it cover $2.8\pi m^2$ area

In $50$ revolution area covered $=50\times 2.8\pi$

Area $=140.0\pi m^2$

Area $=140\times 3.14$

[Area$=43.960m^2$]

$\therefore$ Area covered in $50$ revolution is $439.60m^2$.