Water in a canal, 6 m wide and 1.5 m deep, is flowing with a speed of 10 km/h

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

Let the area that can be irrigated in 30 minute be A m2.

Water flowing in canal in 30 minutes = (10,000 m × ½)

= 5000 m

Volume of water flowing out in 30 minutes = (5000 × 6 × 1.5) m3

= 45000 m3

Volume of water required to irrigate the field = A × 8/100 m3

Equating both equations, we get

A × 8/100 = 45000

A = 562500 m2