Question

A rectangular revisor is 120m long and 75 m wide . Find the speed of the water flowing into it . Through a square pipe of 20 cm side such that the water rises by 1.2 m in 9 hours.​

Answer 1

Answer:

Solution:-

Length of the reservoir = 120 m

Breadth of the reservoir = 75 m

The height of the water level in 18 hours = 2.4 m

Volume of the water collected in the reservoir 120 × 75 × 2.4

= 21600 m³

Let the speed of the flowing water = x m/hr

the water flowing in the pipe eventually forms a cuboid of width 20 cm or 0.2 m and height of 20 cm or 0.2 m.

The length of the cuboid so formed in the pipe in 18 hours = 18x m

Therefore, the volume of the water flows out of the pipe in 18 hours = 0.2 × 0.2 × 18x

= 0.72x m³

Therefore,

Volume of the water collected in the reservoir = volume of the water flows out of the pipe in 18 hours.

21600 = 0.72x

x = 21600/0.72

x = 30000 m/hr

Or, speed of the water = 30 km/hr