Question

If surface area of a sphere in $5544{cm}^2$, then find its volume.

Answer 1

Let radius of sphere be r, then
Given, surface area of sphere $=5544{cm}^2$
$\begin{array}{cc}4\pi r^2=5544& \\ 4\times \frac{22}{7}\times r^2& =5544\\ r^2& =\frac{5544\times 7}{4\times 22}\\ & =441\\ r& =\sqrt{441}\end{array}$
$\begin{array}{cc}& =\sqrt{21\times 21}\\ & =21cm\\ \therefore \text{Volume of sphere}& =\frac{4}{3}\pi r^3\\ & =\frac{4}{3}\times \frac{22}{7}\times 21\times 21\times 21\\ & =38808{cm}^3\end{array}$
Hence, volume of sphere $=38808{cm}^3$