Question

Find the volume of a sphere whose surface area is $154{\text{cm}}^2.$

Answer 1

Let the radius of the sphere be $r.$

Surface area $=154c{m}^2$

$4\pi r^2=154$

$4\cdot \frac{22}{7}\cdot r^2=154$

$r^2=\frac{154\times 7}{22\times 4}$

$=12.25$

$r=3.5cm$

Volume of sphere $=\frac{4}{3}\pi r^3$

$=\frac{4}{3}\times \frac{22}{7}\times 3.5\times 3.5\times 3.5$

$=179.67c{m}^3$

Hence, the volume of the sphere is equal to $179.67c{m}^3.$