A severe thunderstorm dumped 2.4 in of rain in 30 min on a town of area 35 km2. What mass of water (in kg) fell on the town? One cubic meter of water has a mass of 103 kg.

Answer 1

Time is extraneous in this problem.
Mass = Volume x Density
Volume = [35 x 1000 x 1000 m^2] [2.4 x 2.54 / 100 m] = 2,133,600 m^3
Density = 103 kg / m^3
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Mass of rain that fell = 2,133,600 m^3 x 103 kg / m^3 = 219,760,800 kg