Question

Water in a canal, 5.4 m wide and 1.8 m deep, is flowing with the speed of 25 km/h. How much area can it irrigate in 40 min. , if 10 cm of standing water is required for irrigation.

Answer 1

b= 5.4 m
h=1.8m

v= 25 km/h
therefore, l=25km per hour
therefore water that would be flowing in 40 minutes=40*25/60=50/3km=50000/3m

area of irrigation= area water flowing in 40minutes
volume of water which irrigates the land= volume water flowing from canal in 40 minutes

and 10 cm or 1/10 m of standing water is required for irrigation
therefore,
l*b*h=L*B*H
l*b*1/10=50000/3*5.4*1.8
l*b=300000*5.4
l*b=16200000sq. m
therefore, area to be irrigated when 10 cm of standing water is required=16200000sq. m

Answer 2

Hope this helps.....