We have,
Width of the canal = 30 dm = 300 cm = 3 m
Depth of the canal = 12 dm = 120 cm = 1.2 m
It is given that the water is flowing with velocity 10 km/hr. Therefore length of the water column formed in hour = 5 km = 5000 m
∵ Volume of the water flowing in hour
= Volume of the cuboid of length = 5000 m,
Width = 3 m and depth = 1.2 m
= 5000 x 3 x 1.2 m3 = 18000 m3.
Suppose xm2 area is irrigated in hour. Then,
Hence, the canal irrigates 22500 m2 area in hour.