Investigating Stokes Law: Different Formulas, Different Results?

AI Thread Summary
The discussion centers on the differences between two formulas derived from Stokes' Law for calculating the settling velocity of particles. The first formula presented is Vt=gd^2(Pp-Pm)/18u, while the second is V=2/9*d^2*g*(Pp-Pm)/u. The user is confused about why these formulas yield different results despite both being related to the same physical principle. It is noted that the two formulas are essentially equivalent, with the difference arising from the constants used in their derivation. Understanding these constants and their context can clarify the apparent discrepancy.
LaurenG
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Hello all.

I'm investigating a little bit about stokes law in order to understand the settling velocity of falling particles and on the net i encountered with 2 different formulas and i simply can't find the reason why they are different. every formula gives me a different answer.
The 2 formulas are :
1. Vt=gd^2(Pp-Pm)/18u -
stokes_law_terminal_velocity.png

2. V=2/9*d^2*g*(Pp-Pm)/u -
3dbef61d20c1951c09a727ff8d4a809c.png


Any idea why they are different ?
Thanks.
 
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d=2R
 
davieddy said:
d=2R

Silly me, i knew it's something stupid.
Thanks :)
 
So I know that electrons are fundamental, there's no 'material' that makes them up, it's like talking about a colour itself rather than a car or a flower. Now protons and neutrons and quarks and whatever other stuff is there fundamentally, I want someone to kind of teach me these, I have a lot of questions that books might not give the answer in the way I understand. Thanks
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