Find the volume of a sphere whose radius is
(i) $ 7 \mathrm{~cm} $
(ii) $ 063 \mathrm{~m} $.

AcademicMathematicsNCERTClass 9

Given:

Radius of a sphere is

(i) \( 7 \mathrm{~cm} \)
(ii) \( 063 \mathrm{~m} \).

To do:

We have to find the volumes of the sphere in each case.

Solution:

We know that,

Volume of a sphere of radius $r$ is $\frac{4}{3} \pi r^3$

Therefore,

(i) Volume of the sphere of radius $7\ cm= \frac{4}{3} \pi (7)^3$

$=\frac{4}{3} \times \frac{22}{7} \times (7)^3$

$= \frac{4312}{3}\ cm^3$

Hence, the volume of the sphere is $\frac{4312}{3}\ cm^3$

(ii) Volume of the sphere of radius $0.63\ m= \frac{4}{3} \pi (0.63)^3$

$=\frac{4}{3} \times \frac{22}{7} \times (0.63)^3$

$=\frac{4}{3} \times 22 \times (0.63)^2 \times 0.09$

$=88 \times 0.3969 \times 0.03$

$= 1.0478\ m^3$

$\approx 1.05\ m^3$

Hence, the volume of the sphere is $1.05\ m^3$.

raja
Updated on 10-Oct-2022 13:46:39

Advertisements