$18\mathrm{.}10$ A copper smelter processes $1000$ metric tons of ore per day, principally

$CuFe{S}_2,$ producing $S{O}_2$ as a pollutant. The stack is $80$ m tall and $2$ m in exit diameter,

and heat loss through the stack is $3000k\frac{J}{s}.$ For an overcast night with a wind speed

$($measured at $5$ m $)$ of $4\frac{m}{s}$ :

a$.$ Calculate the effective stack height.

b$.$ Calculate the maximum ground level concentration of $S{O}_2.$

c$.$ Estimate the percent $S{O}_2$ control needed to meet the EPA $24-$h secondary

ambient air quality standard $($see Chap. $20).$