Question

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

Answer 1

$\text{Surface area of a sphere}=154{\text{cm}}^2$
$\text{We know, Surface area of a sphere}=4\pi r^2$
$\text{So,}4\pi r^2=154$
$4\times \frac{22}{7}\times r^2=154$
$r^2=\frac{49}{4}$
$r=\frac{7}{2}=3.5cm$
Radius (r) = 3.5 cm
Now,
$\text{Volume of sphere}=\frac{4}{3}\pi r^3$
$=\left(\frac{4}{3}\right)\pi \times {3.5}^3$
$=179.66c{m}^3$
${\text{Therefore, Volume of the sphere is 179.66 cm}}^3.$