A canal is 300 cm wide and 120 cm deep. The water in the canal is flowing with a speed of 20 km/h. How much area will it irrigate in 20 minutes if 8 cm of standing water is desired?

Updated on June 1, 2025 | By Learnzy Admin

Width of canal = 300 cm = 3 m
Depth of canal = 120 cm = 1.2 m
Speed of water = 20 km/h = 20,000 meters per hour = 333.33 meters per minute
Time = 20 minutes

Step 1: Find the volume of water flowing in 20 minutes
Cross-sectional area of canal = 3 m × 1.2 m = 3.6 m²
Distance water flows in 20 minutes = 333.33 × 20 = 6666.67 meters

Volume = area × distance = 3.6 × 6666.67 = 24,000 m³

Step 2: Find the irrigated area
Required water depth = 8 cm = 0.08 m
Area = volume ÷ depth = 24,000 ÷ 0.08 = 300,000 m²

Hence 300,000 m² will be irrigated.

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