Water in a canal, 6m wide and 1.5 m deep, is flowing at a speed of 4km/h. How much area will it irrigate in 10 mins, if 8cm of standing water is needed for irrigation ??

Depth of the canal, = 1.5 m

It is given that water is flowing at a speed of 4 km/hr = 4000m/hr

Thus, length of water column formed in 10 minutes = (1/6) hour = (1/6) x 4000 = 666.67 m

Hence, Volume of the water flowing in (1/6) hour = Volume of the cuboid of length 666.67 m, width 6 m and depth 1.5 m

rightwards double arrowVolume of the water flowing in (1/6) hour

= 666.67 x 6 x 1.5 = 6000.03 = 60000 m^{3} (approx.)

Suppose x m^{2} area is irrigated in (1/6) hour, Then

x cross times 8 over 100 equals 6000 rightwards double arrow x equals 600000 over 8 m to the power of 2 space end exponent equals 75000 space m