Question:
The volume of a sphere is 38808 cm3. Find its radius and hence its surface area.
Solution:
Volume of the sphere = 38808 cm3
Suppose that r cm is the radius of the given sphere.
$\therefore \frac{4}{3} \pi r^{3}=38808$
$\Rightarrow r^{3}=\frac{38808 \times 3 \times 7}{4 \times 22}=9261$
$\Rightarrow r=\sqrt[3]{9261}=21 \mathrm{~cm}$
$\therefore$ Surface area of the sphere $=4 \pi r^{2}$
$=4 \times \frac{22}{7} \times 21 \times 21$
$=5544 \mathrm{~cm}^{2}$