Question

Find the volume of a sphere sphere whose diameter is,
(i) 14 cm (ii) 3.5 dm (iii) 2.1 m

Answer 1

(i) Diameter of a sphere = 14 cm
$\therefore Radius\left(r\right)=\frac{14}{2}=7cm\therefore Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\times \frac{22}{7}\times 7\times 7\times 7c{m}^3=\frac{4312}{3}=1437.33$
(ii) Diameter of a sphere = 3.5 dm
$\therefore Radius\left(r\right)=\frac{3.5}{2}=\frac{7}{2\times 2}=\frac{7}{4}dm\therefore Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\times \frac{22}{7}\times \frac{7}{4}\times \frac{7}{4}\times \frac{7}{4}d{m}^3=\frac{539}{24}=22.46d{m}^3$
(iii) Diameter of a sphere = 2.1 m
$\therefore Radius\left(r\right)=\frac{2.1}{2}=\frac{21}{20}m\therefore Volume=\frac{4}{3}\pi r^3=\frac{4}{3}\times \frac{22}{7}\times \frac{21}{20}\times \frac{21}{20}\times \frac{21}{20}{m}^3=\frac{4851}{1000}=4.851m^3=4.85m^3$