Consider the air over a city (60x25 km). wind with 18 km/hr speed brings the fresh air into the city from the west side of the region (25 km wide). assume that 15 kg/s carbon monoxide (co) is emitted from different sources in the city to the air. assume, also, that the co is conservative and uniformly spread all over the area up to an altitude of one kilometer. modeling the air over the city as a steady-state system, find the co concentration of the air over the city in ppm if the temperature is −20oc and pressure is 1 atm.