Question

The radius of a roller is $60cm$ and its length is $84cm$. Find the area of the ground pressed by it in $500$ revolutions.

Answer 1

Roller is in the form of a cylinder

Radius$=60$cm

Area of the roller$=$Curved surface of cylinder$=2\pi rh$

$\Rightarrow 2\pi rh=2\times \frac{22}{7}\times 60\times 84{cm}^2$

$=15,840‬{cm}^2$

Area of $1$ revolution $=$Area of roller$=15,840‬{cm}^2$

Area of $500$ revolution$=500\times 15840{cm}^2=79,20,000{cm}^2=7,920,000\times \frac{1}{100}\times \frac{1}{100}{m}^2=792m^2$