Question

Water in a canal, 6 m wide and 1.5 m deep, is
flowing at a speed of 4 km/h. How much area
will it irrigate in 10 minutes if 8 cm of standing
water is needed for irrigation? (CBSE 2014)​

Answer 1

Answer:

the required area is 187500 m²

Step-by-step explanation:

area of cross-section = 6×1.5

                                   =9m²

speed of water=10km/h = 10×1000/60 m/min

volume of water that flows in 1min from canal=9×10000/60 = 1500m³

volume of water that flows in 10 mins from canal =1500×10 = 15000m³

let the irrigated area be x.

volume of water flowing in 10 mins from canal= volume of water irrigating the required area

15000=A×8cm

15000=A×8/100 m

15000×100/8 =A

⇒A= 187500m²