$1kg$ of chlorine gas is released instantaneously. For a residential are $500$ m away

If the wind is blowing toward the residential area at $2\frac{m}{s},$ how long until the center of the cloud enters the residential area.

What is the maximum concentration in the residential area? $($use the stability conditions that produce the maximum$).$ Report in $m\frac{g}{m^3}$

From Chemical Process Safety, Third Edition, By Daniel A$.$ Crowl and Joseph F$.$ Louvar $($ISBN: $0131382268)$

Figure $5-12$ Dispersion coefficients for Pasquill$-$Gifford puff model.