Why is Density Necessary in the Viscosity Comparison Method?

Click For Summary
Density is essential in the viscosity comparison method because it directly influences the flow characteristics of liquids in the Ubelohde viscometer. The equation incorporates density to ensure that viscosity is accurately compared between known and unknown liquids, as it accounts for variations in liquid density that affect flow times. Neglecting density would lead to inaccurate viscosity calculations, as weight alone does not provide a complete picture of a liquid's behavior under flow conditions. The relationship established shows that viscosity is proportional to density and time, highlighting the importance of density in maintaining dimensional consistency. Thus, density is a critical factor for accurate viscosity measurements in this method.
thedy
Messages
77
Reaction score
0
Hi,I don know if my question will be clear,but I will try it.So,I m wondering how was derive this equation:
viscosity=viscosity(known liquid)*density(known from table)*time(liquid will get over one point of Ubelohde viscometer to second point of viscometer(unknown liquid)/density(known liquid)*time(liquid will get over one point of Ubelohde viscometer to second point of viscometer(unknown liquid).
So once again in short form:viscosity*density*time/density*time.
So,I know it is a comparison method,that means density*time/density* time is undimensional and that means,that viscosity=density*time in this case.
And now my question:Why density in this equation?Why not only weight?Or why not to neglect density and count only time?Why is density necessary here?
Thanks for patient and widespread answer.
 
Physics news on Phys.org
In this viscometer design, apparently the viscosity times density times time for flow is a constant.
 

Thread 'Does acceleration affect impact energy vs constant velocity?'

I do not have a good working knowledge of physics yet. I tried to piece this together but after researching this, I couldn’t figure out the correct laws of physics to combine to develop a formula to answer this question. Ex. 1 - A moving object impacts a static object at a constant velocity. Ex. 2 - A moving object impacts a static object at the same velocity but is accelerating at the moment of impact. Assuming the mass of the objects is the same and the velocity at the moment of impact...
View full post »

Similar threads

Why is solid density used in this thermodynamics problem?
  • · Replies 5 ·
Replies
5
Views
2K
How Do Viscous Interactions Differ in Vertical and Horizontal Geometries?
  • · Replies 31 ·
2
Replies
31
Views
4K
Undergrad The electron as a smeared charge density
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad What would happen if dark energy density decreased?
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Meaning of the inertial energy density
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Non-equilibrium Statistical Mechanics of Liquids
  • · Replies 3 ·
Replies
3
Views
2K
Applying the ideal gas law in the Earth's atmosphere
  • · Replies 1 ·
Replies
1
Views
3K
Coursework help - Stokes Law equation + graphs
  • · Replies 3 ·
Replies
3
Views
5K
Methods used to measure the density of solid materials and liquids.
  • · Replies 1 ·
Replies
1
Views
52K
Graduate Power spectral density of a laser's frequency noise
  • · Replies 6 ·
Replies
6
Views
2K