B$.$ Particle Size Analysis By Boyucous Hydrometer

Using Stokes's Law, calculate the time needed for all sand particles $($diameter $>50m)$ to settle out of a depth of $0\mathrm{.}2m$ in an aqueous suspension at $20C.$ How long for all silt particles $($diameter $>2m)$ to settle out? For "coarse" clay particles $($diameter $>1m)?$ Assume spherical particles with an average particle density of $2\mathrm{.}65\frac{g}{c}{m}^3$ and a water density of $1\mathrm{.}00\frac{g}{c}{m}^3.$

$\backslash$table$[[$Particle Type,Settling Time$],[$Sand$,],[$Silt$,],["$Coarse$"$ Clay,$]]$

Another portion of the same soil sample was passed through a #$10$ sieve to isolate just the $<mn>2</mn><mi>m</mi><mi>m</mi>$ fraction. A $40\mathrm{.}0g$ sample of the sieved soil was then mixed with water and chemically and mechanically dispersed $($as seen in the video linked to the lecture$).$ The temperature and hydrometer reading were taken at the following times.

a$.$ Fill in the table on the next page. Calculate the percent passing and plot a particle size distribution graph for the hydrometer analysis.

b$.$ Determine the $\%$ sand, $\%$ silt, and $\%$ clay in the sample based on the criteria for both the USDA and the ASTM particle size classifications. Then use the USDA soil textural triangle to assign a soil texture to the soil based on each classification.

$\backslash$table$[[,\%$ Sand,$\%$ Silt,$\%$ Clay $($or Fines$),$Soil Texture$],[$USDA$,,,,],[$ASTM$,,,,]]$

What are the limitations of this analysis? Does it do a better job of describing larger or smallersized particles? What are the implications of this for a soil high in sands? High in clays?

Name

$\backslash$table$[[$Time$,\backslash$table$[[$Temperatur$],[$e$],[(C)$ Please give answers to all the questions detailed as soon as possible