Question

A rectangular tank is 80 m long and 25 m broad. Water-flows into it through a pipe whose cross-section is $25c{m}^2,$ at the rate of 16 km per hour. How much the level of the water rises in the tank in 45 minutes.

Answer 1

$\text{Length of tank (l)}=80m$

$\text{Breadth (b)}=25m$

$\text{Area of cross section of the month of pipe}=25c{m}^2$

$\text{and speed of water-flow}=16km/h$

$\therefore \text{Volume of water in 45 minutes}$

$=\frac{16\times 3}{4}\times 1000\times \frac{25}{10000}{m}^3$

$=\frac{12\times 25}{10}=\frac{300}{10}=30m^3$

$\therefore \text{Level of water in the tank}$

$=\frac{\text{Volume of water}}{\text{Area of tank}}$

$=\frac{30}{80\times 25}m=\frac{3}{200}m$

$=\frac{3}{200}\times 100cm=1.5cm$