Question

The diameter of a garden roller is $1.4m$ and it is $2m$ long. How much area will it cover in $5$ revolutions? (Use $\pi =\frac{22}{7}$)

• A. $40m^2$
• B. $41.40m^2$
• C. $44m^2$
• D. $42.40m^2$

Answer 1

The correct option is C $44m^2$

Since the diameter of the roller is
$0.7m$, its radius is $0.35m$.

The roller is in the shape of a cylinder.

In one revolution, the roller covers the distance of one curved surface area.

Curved Surface Area of a Cylinder of Radius "$R$" and height "$h$" $=2\pi Rh$

Radius of the roller $=0.7m$

Curved Surface Area of the roller of radius $0.35m=2\times \frac{22}{7}\times 0.7\times 2=8.8m^2$

Area covered in $5$ revolutions $=5\times 8.8m^2=44m^2$