Calculation example - Determine the specific gravity of a soil grain Gs

Calculate the ratio of the density of coal ash to the density of the water (Specific gravity of coal ash Gs)

Known values:

A 90 g sample of coal ash.

Total mass of pycnometer (a density bottle) with coal ash inside and filled with water = 720 g.

Mass of clean pycnometer filled only with water = 670 g

Solution:

Step 1: Find the mass of the water displaced by coal ash (i.e , same volume V) using Archimedes' principle.

 Step 2: Specific gravity of coal ash calculation

 here:

ρ_s the density of the dry coal ash

ρ_w the density of the water displaced by coal ash inside pycnometer