Question

Water in a canal, 5.4m wide and 1.8 m deep, is flowing with a speed of 25km/he. How much area can it irrigate in 40 minutes if 10cm of standing water is required?

Answer 1

Hi there !!


Breadth , b = 5.4 m

Height[depth] , h = 1.8 m

Speed of canal = 25 km/hr


Length of canal in 1 hour = 25 km


Length of canal in 60 minutes = 25 km                         [ 1 hr = 60 min ]

Length of canal in 1 min = $\frac{25}{60}$

Length of canal in 40 min = $\frac{25}{60}$ × 40

                                          = 16.67 km [ approx . ]

                                          = 16670 m


Volume of canal =  l b h 

                           = 16670  × 5.4  × 1.8 m
                          
                           = 162032.4 metres


Height of standing water = 10 cm = 0.1 metres

Volume of water in canal = Volume of area irrigated

Volume of area irrigated = Area irrigated × height

162032.4 metres = Area irrigated × 0.1

Area irrigated =   162032.4 ÷ 0.1

                       = 1620324 m²

1m² = 0.0001 hectares 

Area irrigated =  162.0324 hectares