Question

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 for irrigation ?

Answer 1

$\textbf{\underline{\underline{According\:to\:the\:Question}}}$  

Suppose the area that can be irrigated in 30 minutes  

= A m^2.

Water flowing in canal in 30 minutes

${\implies 10000\times \dfrac{1}{2}m}$      

= 5000 m  

Volume of water flowing out in 30 minutes

= (5000 × 6 × 1.5) m^3

= 45000 m   ......... (1)

Volume of water required to irrigate the field

${\implies A\times \dfrac{8}{100}m^{3}}$  ...... (2)

Equating (i) and (ii)

${\implies A\times \dfrac{8}{100}m^{3} = 45000}$

A = 562500 m^2.