A river $ 3 \mathrm{~m} $ deep and $ 40 \mathrm{~m} $ wide is flowing at the rate of $ 2 \mathrm{~km} $ per hour. How much water will fall into the sea in a minute?

Given:

A river $3\ m$ deep and \( 40 \mathrm{~m} \) wide is flowing at the rate of \( 2 \mathrm{~km} \) per hour. 

To do:

We have to find the amount of water that falls into the sea in a minute.

Solution:

Area of the river $=$ Depth $\times$ Width

$=3\times40\ m^2$

$=120\ m^2$

Amount of water that falls into the sea in a minute$=$ Area of the river $\times$ Flowing rate

$=120\times(\frac{2\times1000}{1\times60})\ \frac{m^3}{min}$ 

$=4000\ \frac{m^3}{min}$ 

$4000\ m^3$ of water will fall into the sea in a minute.