Question

a river 3.5 m deep and 28 m wide is flowing at the rate of 2.4 km per hour. how many litres of wate will flow into sea in 10 minutes

Answer 1

Rate of flow of water = 2.4km per hour = 2.4×5/18 m/sec
= 0.6 m/sec
10 min = 600 sec
volume of water flow into the sea = 3.5 × 28 × 0.666667 ×600
= 39200 m³

Answer 2

we use the formula for the volume of a cuboid.

Its length will be as much as the distance water travels in 10 minutes.

volume of water flowing into the sea = 28 m * (2,400 * 1/6)m  * 3.5 m 
       = 39, 200 cubic meters