Practice question · Multiple choice
Rain falls with varying intensity over a city. What does compute?
Hints
- Each patch catches of water. The double integral adds up the patches.
- Integrating intensity (depth/time) over area gives volume/time. To get the average, you would divide by the city’s area.
Show the answer
D. The total volume per unit time
Why
A double integral is a weighted total: local rate × patch area, summed to the whole. Divide by and you get the average intensity, total and average are the two faces of every double integral.
Practise Double Integrals
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