A solute plume is spreading in a pipe containing water. You were provided the spatial variance of the plume measured at two consecutive times as reported below: Time Variance (cm?) 2:00 pm 1600 4:00 pm 1700 Compute the diffusion coefficient using the measured variances. Comment on the computed value. Is the water stagnant or moving? For simplicity consider that: Y marer = 10- m /s ; Vair =10m / 5 ; Density of air=1.0 kg/m