Question

Water in a canal 1.5 m wide and 6 m deep is flowing with a speed of $10\frac{km}{hr}$ .How much area will it irrigate in 30 minutes if 8 cm of standing water is desired?

Answer 1

Answer:

The required area for covering 8 cm or 8/100 m height of standing water = 56.25 hectare

Step-by-step explanation:

Given :  

Breadth of a canal , b = 6 m

Height of a canal , h = 1.5 m

Speed of flow of water from canal = 10 km/h  

= 10 × 1000 m/h = 10000 m/h  

[1 km = 1000 m]  

Length of water flows in 1 hour , l = 10000 m  

Volume of water flowing from canal in 1 h = l × b × h

= 10000 × 6 × 1.5 = 90000 m³

Volume of water flowing from canal in 1 h = 90000 m³

Volume of water flowing from canal in 1/2 h(30 min) = ½ × 90000 = 45000 m³  

Area for covering 8 cm or 8/100 m height of standing water = 45000/8 × 100 = 562500 m² = 562500/10000 hectare = 56.25 hectare

[ 1 hectare = 10000 m²]

Hence, the required area for covering 8 cm or 8/100 m height of standing water = 56.25 hectare

HOPE THIS ANSWER WILL HELP YOU…. ..

Answer 2

Canal dimensions :

Height = 6m

Width = 1.5m

Length = 10km = 10000m (because speed = 10km/hr)

Time to irrigate = 30mins = 1/2 hr

Height (standing water) = 8cm = 0.08m

ATQ,

Vol. Of canal * t = vol. Irrigated

6 * 1.5 * 10000 * 1/2 = lb * 0.08

90 * 10000 * 1/2= lb * 8/100

lb = 450000 * 100 / 8
lb = 5625 hectares