Question

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

• A. $6.8$ $m^2$
• B. $8.8$ $m^2$
• C. $3.8$ $m^2$
• D. $5.8$ $m^2$

Answer 1

The correct option is B $8.8$ $m^2$

$\Rightarrow$ Diameter of the roller $\left(d\right)=1.4m$.

$\Rightarrow$ Radius of the roller $\left(r\right)=\frac{1.4}{2}=0.7m.$

$\Rightarrow$ Length of the roller $\left(h\right)=2m.$

If the roller complete one revolution

Then the area covered $=$ Curved surface area of the roller $=2\pi rh$

$\Rightarrow$ Area covered in $1$ revolution $=2\pi rh$

$=2\times \frac{22}{7}\times 0.7\times 2$

$=88\times 0.1$

$=8.8m^2$