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?​

Answer 1

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✤ Required Answer:

✒️ GiveN:

• Height and width of canal = 1.5 m and 6 m
• Water flowing at speed = 10 km/h
• It is irrigated for 30 mins
• Height of standing water = 8cm

✒️ To FinD:

• Area of field irrigated.....?

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✤ How to solve?

First of all, we need to find the length of water that is water flowing in a canal. We have speed of water and time, so we find the distance or length of the water. Then, Height is given for standing water. Volume = Area × Height for any 3-D figure.

⛈️ So, Let's solve this question.....$.$

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✤ Solution:

Here, we can imagine the canal is in the form of cuboid.

• h = 1.5 m
• b = 6 m

Finding the length,

Given, Speed of canal = 10 km/hr

➝ Length of canal in 1 hr = 10000 m

➝ Length of canal in 30 mins = 10000/2 m

➝ Length of canal in 30 mins = 5000 m

Finding volume of water in canal,

➝ Volume of cuboid = l × b × h

➝ So, Volume of water = 5000 m × 6 m × 1.5 m

➝ Volume of water in canal = 45000 m³

[ As we are irrigating the field with the volume of water in the canal, the volume of water in canal = Volume of standing water in the field. ]

So,

➝ Volume of water in canal = Volume of standing water.

➝ 45000 m³ = Area of irrigation × height

➝ 45000 m³ = Area of irrigation × 0.08 m

Flipping it,

➝ Area of irrigation × 0.08 m = 45000 m³

➝ Area of irrigation = 45000 m³ / 0.08 m

➝ Area of irrigation = 4500000 / 8 m³

➝ Area of irrigation = 562500 m²

We know,

• 10000 m² = 1 hectare

Then,

➝ 562500 m² = 56.25 hectare

➝ Area of irrigation = 56.25 hectare

⚘ Hence, solved !!

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