Question

A river 1.5 m deep and 36 m wide is flowing at the rate of 3.5 km/hr. Find the amount of water (in cubic metres) that runs into the sea per minute.

Answer 1

We have, 

Depth of the river, h = 1.5 m,

Width of the river, b = 36 m,

Speed of the flowing water,` l = 3.5 "km"//"hr" =(3.5xx1000  "m")/(60  "min") = 175/2 "m"//"min"`

Now,

The amount of water that runs into sea per minute = lbh

`=175/3xx36xx1.5`

= 3150 m³ / min

So, the amount of water that runs into the sea per minute is 3150 m³.