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Ex.13.8 Q1 Surface Areas and Volumes Solution - NCERT Maths Class 9

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Question

Find the volume of a sphere whose radius is

(i) \(7 \rm cm\)     

(ii) \(0.63 \rm m\)

 Video Solution
Surface-Areas-And-Volumes
Ex exercise-13-8 | Question 1

Text Solution

Reasoning:

Volume of the sphere \(\begin{align} = \frac{4}{3} \end{align}\) \(\pi r^{3}\)

What is  known?

Radius of the spheres.

What is unknown?

Volume of the sphere.

Steps:

(i) Radius  \(=7 \rm cm\)

Volume of the sphere

\[\begin{align}&= {\frac{4}{3}} \\ &= \frac{4}{3} \times \frac{{22}}{7} \times {7^3}\\ &= 1437.33\,\,c{m^3} \end{align}\]

(ii) Radius \(=0.63 \rm m\)

Volume of the sphere

\[\begin{align}&=\frac{4}{3} \pi r^{3}\\&= \frac{4}{3} \times \frac{{22}}{7} \times {(0.63)^3}\\ &= 1.05\,\,{m^3}\end{align}\]

Answer:

Volume (\(i\)) \(\begin{align} = 1437.33\,\,c{m^3} \end{align}\)

Volume (\(ii\)) \(\begin{align} = 1.05\,\,{m^3} \end{align}\)