GIVEN: A simple way to model air pollution over a city is with a box model that assumes complete mixing and limited capability for the pollution to disperse horizontally or vertically except in the direction of the prevailing winds (for example, a town located in a valley with an inversion layer above it). Consider a town having an inversion at 250 m, a 20-km horizontal distance perpendicular to the wind, a windspeed of 2 m/s, and a carbon monoxide (CO) emission rate of 60 kg/s .Assume the CO is conservative and completely mixed in the box.
FIND: What would be the CO concentration in the box?