Question

A river $2m$ deep and $45m$ wide is flowing at the rate of $3km$ per hour. Find the volume of water that run into the sea per minute.

Answer 1

Given that rate of flow $3km/h$

Depth (h) of river $=2m$

Width (b) of river $=45m$

Area of cross-section of river$=$Depth$\times$width

$$\begin{gathered} =45\times 2 \\ =90m^2 \end{gathered}$$

Rate of flow 3 km/h$=3\times \frac{1000}{60}$

$=50m/min$

Volume of water is flowing in cross-section in $1$ minute is$=90\times 50=4500m^3/minute$