Answer:

Step-by-step explanation:
v = Velocity of the breeze = 4 m/s
w = Width of the valley = 5000 m
h = Height of the valley = 1000 m
Volumetric flow rate is given by

= Mass flow rate of pollutant = 25 g/s =

Concentration is given by

The steady state concentration of pollutants in the valley, is
.