$5-12.$ Develop a spreadsheet to determine the isopleths for a puff at a specified time after the release of

material. The spreadsheet should contain specific cells for user input of the following quantities: time after

release $($s$),$ wind speed $(2\frac{m}{s}),$ total release $(kg),$ release height $($m$),$ molecular weight of released gas, ambient

temperature $(K),$ ambient pressure $($atm$),$ and isopleth concentration $($ppm$).$

The spreadsheet output should include, at each point downwind, the downwind location, both $y$ and $z$

dispersion coefficients, downwind centerline concentration, and isopleth distance off$-$center $(+/-).$

The spreadsheet output should also include a graph of the isopleth location.

For your spreadsheet construction, we suggest that you set up the cells to move with the puff center.

Otherwise, you will need a large number of cells.

Use the spreadsheet for the following case:

Release mass: $0\mathrm{.}5kg$

Release height: $0m$

Molecular weight of gas: $30$

Ambient temperature: $298K$

Ambient pressure: $1$atm

Isopleth concentration: $1ppm$

Atmospheric stability: F

Run the spreadsheet for a number of different times, and plot the maximum puff width as a function of distance

downwind from the release.

Answer the following questions:

a$.$ At what distance downwind does the puff reach its maximum width?

b$.$ At what distance and time does the puff dissipate?

c$.$ Estimate the total area swept out by the puff from initial release to dissipation.

Your submitted work should include a description of your method of solution, a complete spreadsheet output at

$2000s$ after release, a plot of maximum puff width as a function of downwind distance, and the calculation of

the total swept area.