Question

Water in canel 6 m wide and 1.5 m deep is flowing with the speed of 10kmph how much are will it irrigate in 30 min if 8cm standing water is needed.

Answer 1

$\textit{\textbf{\underline{Since we know that,}}}$

Volume of cuboidal shaped pipe = l × b × h

= 6 m × 1.5 m × 10 km/hr

$\textsf{But units matter too therefore,}$

10 km/hr = 10,000 m/hr

= 6 × 1.5 × 10,000 m³/hr

$\bold{= 90,000\:{m}^{3} /hr}$

Now, this V of water flowed for 30 mins.

= 90,000 m³/hr × 30/60 hr

$\bold{=\:45,000\:m^3}$

This volume of water stands to height of 8 cm or 8/100 m.

Area × height = Volume

Area × 8/100 = 45000

Area = 45000 × 100/8

Area = 5,62,500 m²

$\Longrightarrow{\boxed{\bold{Answer\:is\:562500\:m^2}}}$

Answer 2

here is your answer ☺☺☺☺☺☺


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