Question

8. Water in a canal, 6 m wide and 1.5 m deep, is flowing with a speed of 10 km/h. How much
area will it irrigate in 30 minutes, if 8 cm of standing water is needed?
​

Answer 1

Speed of water= 10km/h= 25/9 m/s
Volume of water flowing in 1 second = (6*1.5*25/9)= 25 meter cube
Volume of water that flowed in 30 min= volume of water in 1 second * time (in second)
=25*30*60.
=45000 meter cube

Now; Volume of field irrigated= Volume
of water drained
=>L*B*H= 45000
=>Area*height=45000 [L*B=Area]
=> Area*8= 45000
Therefore; Area=5625