A school in Jaipur has a rooftop area of 300 m². During the monsoon, the average rainfall is 750 mm and the runoff coefficient for the roof is 0.8. What is the maximum volume of rainwater that can be harvested from the roof?
Answer
180 m³
The correct answer is 180 m³ — Thus the maximum harvestable volume is 180 m³.
Step-by-step solution
- Convert the rainfall depth from millimetres to metres: 750 mm = 0.75 m.
- Multiply the area of the roof by the rainfall depth to get the total volume of water that falls: (300,\text{m}^2 \times 0.75,\text{m} = 225,\text{m}^3).
- Apply the runoff coefficient to obtain the volume that can actually be harvested: (225,\text{m}^3 \times 0.8 = 180,\text{m}^3).
- Thus the maximum harvestable volume is 180 m³.
Common mistake: Not converting rainfall depth from millimetres to metres before multiplying by area
Concept tested: Rainwater harvesting
Published · How this solution was prepared and checked
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