Question

Water in a canal 6m wide and 1.5m deep is the flowing with a speed of 10km/hr how much are will it irrigate in 30 mins, if 8cm of standing water is needed

Answer 1

given, speed = 10km/hr = 10000m/hr

time = 30 minutes

width of canal = 6 m and height of canal = 1.5 m

cross section area of canal = width of canal * height of canal

= (6 * 1.5 )m2

volume of water flowed from canal in one hour = cross section area * speed of water

= 6 * 1.5 * 10000

=6 * 15000

=90000 m3

volume of water in half an hour = 90000 * 1/2

= 45000 m 3

height of standing water = 25 cm = 0.25 m

volume of water flowed in 30 minutes = volume of water in field

45000 = area * height

45000 = area * 0.08 m

area = 45000/0.08

area = 562500 m2

1 hactare = 10000 m2

so area irrigated in 30 minutes = 56.25 hectares