A conical pit of top diameter $ 3.5 \mathrm{~m} $ is $ 12 \mathrm{~m} $ deep. What is its capacity in kilolitres?

AcademicMathematicsNCERTClass 9

Given:

A conical pit of top diameter $3.5\ m$ is $12\ m$ deep. 

To do:

We have to find its capacity in kilolitres.

Solution:

Diameter of the top of the conical pit $= 3.5\ m$

This implies,

Radius of the top of the pit $(r)=\frac{3.5}{2}$

$=1.75 \mathrm{~m}$

Depth of the pit $(h)=12 \mathrm{~m}$

Therefore,

Volume of the pit $=\frac{1}{3} \pi r^{2} h$

$=\frac{1}{3} \times \frac{22}{7} \times 1.75 \times 1.75 \times 12$

$=38.5 \mathrm{~m}^{3}$

The capacity of the pit in kilolitres $=38.5$ kilolitres                  (Since $1\ m^3 = 1000\ L$ and $1\ m^3 = 1\ kL$) 

raja
Updated on 10-Oct-2022 13:46:38

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