How Do You Calculate the Specific Gravity of Alcohol?

AI Thread Summary
To calculate the specific gravity of alcohol, the buoyant force acting on an aluminum cylinder submerged in alcohol is determined using the scale reading and the weight of the cylinder. The buoyant force is calculated to be 0.298 N, leading to the density of alcohol being found as approximately 781.7 kg/m³. The specific gravity is then calculated using the formula that compares the density of the object to that of the medium. However, the initial calculation of specific gravity as 3.458 was incorrect. The specific gravity of a substance is defined as the ratio of its density to the density of water.
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Homework Statement



An aluminum cylinder weighs 1.03 N. When this same cylinder is completely submerged in alcohol, the volume of the displaced alcohol is 3.89 multiplied by 10-5 m3. If the cylinder is suspended from a scale while submerged in the alcohol, the scale reading is 0.732 N. What is the specific gravity of the alcohol?


Homework Equations



Fscale + FBuoyancy = mg

FBouyancy = DVg

Specific gravity = Dobject / Dmedium

The Attempt at a Solution



First I used Fscale + FBuoyancy = mg
(.732)(FB) = 1.03
FB = .298 N

Then I used FB = DVg
.298 = Dalcohol(3.89e-5)(9.8)
Dalcohol = .298 / [(3.89e-5)(9.8)]
Dalcohol = 781.7009 kg.m3

Then I used Specific gravity = Dobject / Dmedium, where D = mv.

Specific gravity = (m/v) / Dalcohol
Specific gravity = [(1.02/9.8)/3.85e-5] / (781.7009)
Specific gravity = 3.458

I tried this answer and it was wrong. Can anyone help out? Thank you!
 
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Soojin said:
Then I used Specific gravity = Dobject / Dmedium
The specific gravity of a substance is the ratio of the density of that substance to the density of water.
 
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