The physical meaning of some units

Forum|Forum|10 years ago
May 10, 2016
2 replies
5915 views

The physical meaning should be back in the unit of measurement of certain physical quantities.

The examples below. The most striking - a unit of dynamic viscosity. Do you know some others units?

Other

D

DenisJaunin

15-Moonstone

Hi Valery,

See attached some documents.

Kind regards.

Denis

http://www.fimop.be/images/File/formules_fr_deel1.pdf

http://www.nist.gov/pml/div684/fcdc/upload/si_brochure_8.pdf

V

ValeryOchkov

Author

24-Ruby IV

Thanks, Denis (Денис?)

I understand that dynamic viscosity has unit poise or kg/m/s.

But I do not understand Pa*s. I see in dynamic viscosity time but I do not see pressure!

I have wrote aboit it in the first chapter of the book Физико-математические этюды с Mathcad и Интернет - Let go to meanings in formulas and units!

R

Raiko

17-Peridot

Hello Valery,

the definition for this comes from a simple experiment. when you have a (Newtonian) liquid between two parallel plates you can observe that some of the liquid is carried along when moving one plate. The relation of velocity and liquid "resistance" to that motion is expressed as the shearing angle. The resistance itself is measured in units of presssure (N/mm2). Although it is a force parallel to a given surface it has the same physical unit as a force perpendicular to it.

This is quite counter intuitive and I have a hard time explaining this to my collegues from the electrical department.

Raiko

P.S.

Another example might be: bending torque N*m and torsional torque, also in N*m.

L

LucMeekes