Question

The curved surface area of a cylindrical pillar is $264$sq.m and its volume is $924$cu.cm.Find the height of the pillar.

Answer 1

Curved surface area$=2\pi rh=264$sq.cm ........$\left(1\right)$

Volume $=\pi r^{2}h=924$cu.cm .........$\left(2\right)$

$\frac{\left(2\right)}{\left(1\right)}\Rightarrow \frac{\pi r^{2}h}{2\pi rh}=\frac{924}{264}$

$\Rightarrow \frac{r}{2}=\frac{7}{2}$

$\Rightarrow r=7$m

Substituting in $\left(2\right)$ we have

$\frac{22}{7}\times 7\times 7h=924$

$\Rightarrow h=\frac{924}{22\times 7}=6$m

Height of the pillar $=6$m