Question

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

Answer 1

We have

Width of the river $=44m$, Depth of the river $=3m$

If $l$ meter is the length of the river, then the water in the river forms a cuboid of width $40$ metres and height $3$ metres

The length of the cuboid is equal to the distance traveled by water in one minute with the speed of $2km$ per hour

length of the cuboid $=\frac{2000}{60}metres=\frac{100}{3}$ metres

Volume of the water $=\frac{100}{3}\times 40\times 3m^3=4000m^3=4000000$ litres