Posted by Joe on .
An aluminum cylinder weighs 1.03 N. When this same cylinder is completely submerged in alcohol, the volume of the displaced alcohol is 3.90 x 105 m3. If the cylinder is suspended from a scale while submerged in the alcohol, the scale reading is 0.730 N. What is the specific gravity of the alcohol?

physics 
drwls,
In this case the displaced fluid weighs 1.03  0.730 = 0.300 N (the buoyancy force). The displaced fluid mass is 0.300/g = 0.0306 kg. Divide that by the cylinder's volume for the mass density
(demsity) = 0.0306/3.9*10^5
= 784 kg/m^3
Divide that by ths density of water (1000 kg.m^3) to get the specific gravity of the alcohol.