Physics water Question?

Question

A heavy rainstorm dumps 1.0 cm of rain on a city 5 km wide and 8 km long in a 2 h period.

How many metric tons ( 1 metrci ton = 10^3 kg}) of water fell on the city? (1cm^3 of water has a mass of 1 g = 10^ -3 kg}.)

Any help is appreciated.

Answer 1

Mass = mass gamma * Volume  Where mass gamma = 1000 kg/ m^3

Volume = A * h, where A = 5E03 m * 8E03 m * 0.01 m = 400,000 m^3

Mass = 1000 kg/m^3 * 400,000 m^3 = 4E08 kg * 1 mt/1E03 kg = 4E05 metric tons.