Question

MATHS "CLASS X"

SURFACE AREAS AND VOLUMES

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

Ex 13.3
Question 8

Answer 1

volume of canal= 10000×6×1.5= 90000m^3
in 30 minutes, it will be 45000m^3
now, lbh=45000
l×b×0.08=45000
area=45000/0.08=562500m^2 or 56.25ha
Hope it was helpful. Plz mark as brainliest!

Answer 2

${\boxed {\boxed {\boxed {\boxed{\sf{Here's \: the \: answer}}}}}}$


Canal ( cuboid shaped ) =>

Height => 1.5 metre

Breadth => 6 metre

Speed => 10 km/ hr

Now,

Length of canal ,in one min => 1/60 × 10

Length of canal in 30 min => 30/60 × 100
=> 5 km = 5000 metre.

So,

To find volume of the canal,

Using formula ,

Volume of canal = Length × Breadth × Height

$\sf{= 5000 \times 6 \times 1.5}$

$\sf{= 5000 \times 9} \\ \\ \sf {= 45000}$

Thus,

Volume of the canal is 45000 cu.m

1 m = 100 cm

1 cm = 1/100 metre
Thus,

8 cm ( height ) = 8/100 metre

Now,

Volume of canal = Irrigation area × Height

Let the area irrigated be x,

$\sf{45000 = x \: \times \frac{8}{100}}$

$\sf{ \frac{4500000}{8 } = x}$

$\sf{562500 \: {m}^{2} = x}$

Thus,

Area irrigated => 562500 sq. metre.

Thanks!!