A smokestack of height H = 50 m emits a pollutant in a 3 m/s wind. The plume is carried downwind by advection (wind speed U = 3 m/s) and is simultaneously dispersing vertically with a turbulent diffusion coefficient D. The vertical diffusion causes the plume to widen vertically over time, with halfâwidth (distance from centerline to edge) increasing as: half width = 2 â2Dt

The plume reaches the ground some distance L downwind of the base of the smokestack (see sketch in book on page 203)

a. If L = 2 km, estimate the value of the turbulent diffusion coefficient D.
b. Under the same wind speed and turbulence conditions, what would be the value of L if the smokestack were twice as high?

a) 0.46875

b) 8 km

Explanation:

Smokestack height ( H ) = 50 m

speed of pollutant / wind speed = 3 m/s

Half width = 2 = 50 m  ---- ( 1 )

a) If L = 2 km

value of turbulent diffusion coefficient D

back to equation 1

50 = 2 √ 2 * D * ( 2000/3 )

2500 = 4 * 2 * D * ( 2000/3 )

D = 2500 / ( 8 * ( 2000/3 )  )

   = 0.46875

where : time to travel ( t ) = Distance / speed = 2000 / 3

b) when the smoke stack = 50 * 2 = 100 m

L = 800 m = 8 km

attached below is the detailed solution

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

i will answer your question if you answer mine