Verifying Dimensionality of Fall Velocity Equation

AI Thread Summary
The discussion focuses on verifying the dimensionality of the fall velocity equation for a particle in a viscous medium, expressed as Vt = gd^2(Pp - Pm) / 18 u. Participants are asked to demonstrate whether this equation is dimensionally homogeneous by showing the unit cancellation process. One user expresses uncertainty about their calculations, arriving at the conclusion that m/s = m/s x m, and seeks clarification on their mistake. The conversation emphasizes the importance of detailed steps in calculations to identify errors. Overall, the thread aims to ensure a clear understanding of dimensional analysis in the context of the fall velocity equation.
jase03
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The equation for the fall velocity (terminal velocity) of a particle of a material in a viscous medium has been derived from theory as:

Vt = gd^2(Pp - Pm) / 18 u

Where: Vt is the terminal velocity in m/s; g is the acceleration due to gravity; d is particle diameter in m; Pp and Pm are the densities of the particle and the medium (respectively) in kg/m^3; u is the viscocity of the medium in kg/m/s (kg.m^-1.s^-1)

Demonstrate if this equation is dimensionally homogeneous or not. Show your working.


Could someone show me how you work this out with the cancelling of units.

My final answer I'm getting - m/s = m/s x m

I don't think I'm correct.


Regards
Jason
 
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If you show all your steps in the working one can point out where the mistake is.
 
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