Question

the radius and height of a cylindrical cistern 1.4m and 2m respectively. how many litres of water can it hold? (ANS. 115.5 cm²)​

Answer 1

Answer:

Given:

Radius of the Cylindrical cistern= r= 1.4 m = $\frac{14}{10}$ m

Height of the Cylindrical cistern = h= 2 m

To find :

The amount of water it can hold (In Litres), i.e. Volume of the cistern

Proof:

According to the question, the amount of water the cylindrical cistern can hold= The volume of the cistern

Therefore,

The volume of the cistern = $\pi r^{2} h$

$\pi = \frac{22}{7} \\r= \frac{14}{10}m\\h = 2 m$

Substituting the values in the equation, we get :

=$\frac{22}{7} X \frac{14}{10} X \frac{14}{10} X 2$

$=\frac{22 X 14 }{ 5 X 5} \\\\= \frac{308}{25} \\= 12.32 m^{3}$

Now, 1 $m^{3}$= 1000 Litres

Therefore,

$12.32 m^{3} \\ = 12. 32 X 1000 Litres \\= 12320 Litres$

Thus, the cylindrical cistern can hold 12320 Litres of water.