Question

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

Answer 1

Here, Area of river = depth $\times$ width

$=3\times 40=120m^2$

amount of water that falls into the sea $\Rightarrow$ area of river $\times$ flow rate

$\Rightarrow 120m^2\times 2\frac{km}{hr}$

$\Rightarrow 120\times \frac{2\times 1000m^3}{\left(60\right)min}$

$\Rightarrow 4000\frac{m^3}{min}$

$\therefore 4000m^3$ of water falls into the sea permin.