Question

A road roller takes $750$ complete revolutions to move once over to level a road. Find the area of the road if the diameter of a road roller is $84cm$ and length is $1m$.

• A. $1980m^2$
• B. $2080m^2$
• C. $1980c{m}^2$
• D. None of these

Answer 1

The correct option is A $1980m^2$

In one revolution, the roller will cover an area equal to its lateral surface area

$r=\frac{diameter}{2}=\frac{84}{2}=42cm$

Thus in 1 revolution, area of the road covered=$2\pi rh$

$\Rightarrow 2\times \frac{22}{7}\times 42cm\times 1m$

$\Rightarrow 2\times \frac{22}{7}\times \frac{42}{100}m\times 1m$

$\Rightarrow \frac{264}{100}{m}^2$

Hence, area of road covered in $750$ revolution=$750\times \frac{264}{100}{m}^2=1980m^2$