Question

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

Answer 1

Speed of water in canal = 10 km/hr

In 30 min = `30/60` = `1/2` hr

∴ Length of water = `10 xx 1/2`

= 5 km

= 5000 m

Volume of water is canal is 30 min = Volume of water for irrigated

⇒ `6 xx 1.5 xx 5000 = 8/100 xx l xx b`

⇒ `l xx b = (6 xx 1.5 xx 5000 xx 100)/8`

= `(4500000)/8`

= 562500 m²

Hence, area irrigated is 30 min is 562500 m².