Question

Water in a canal, 6 m wide and 1.5 m deep, is flowing with a speed of 10 km/hr. How 3 much area will it irrigate in 30 minutes, if 8 cm of standing water is needed?

Answer 1

Canal is in the shape of cuboid , where,

Breadth $=6$ m

Height $=1.5$ m

Speed of canal $=10$ km/hr

Length of canal in $1$ hour $=10$ km

Length of canal in $60$ minutes $=10$ km

Length of canal in $1$ minute = $\frac{1}{60}\times 10$ km

Length of canal in $30$ minute = $\frac{30}{60}\times 10=5km=5000m$

Now,

Volume of canal = $length\times breadth\times height$

= $5000\times 6\times 1.5$ $m^3$

Now,

Volume of water in canal = Volume of area irrigated

Volume of water in canal = Area irrigated $\times$ Height

$5000\times 6\times 1.5$ = Area irrigated $\times \frac{8}{100}$

Area irrigated = $\frac{5000\times 6\times 1.5\times 100}{8}$

Area irrigated = $562500$ $m^2$

Area irrigated = $\frac{562500}{10000}$ hectares

Area irrigated = $56.25$ hectares