Question

Find the volume of a sphere whose surface area is $154c{m}^2$

Answer 1

Surface area of a sphere = 154 cm
$\therefore Radius=\sqrt{\frac{Surfacearea}{4\pi }}=\sqrt{\frac{154\times 7}{4\times 22}}=\sqrt{\frac{49}{4}}=\frac{7}{2}cm=3.5cm\therefore Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\times \frac{22}{7}\times {\left(\frac{7}{2}\right)}^{3}c{m}^3=\frac{88}{21}\times \frac{7\times 7\times 7}{2\times 2\times 2}c{m}^2=\frac{11\times 49}{3}=\frac{539}{3}=179.66c{m}^3$