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Coulombs date back to the 1860's, and even predate CGS units. The connection between the volt-ohm-second and mks units were made only in 1904. Coulomb used e.s.u. based on the french ft lb s system. The coulomb constant is a feature of choice of units, if charge is found from LMT, then the size of the coulomb constant can be set to one.


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No, Coulomb did not know the Coulomb as a unit. According to this page, the Coulomb was defined at the 9th CGPM (General Conference on Weights and Measures) conference, in 1948. Wikipedia gives the same date. Coulomb could not measure charges, but he could create a charge and then halve it, quarter it, etc by letting the charge flow from one object to ...


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The electric potential at a point is actually defined as such: $$ V={PE \over q} $$ Therefore: $$PE=qV $$ It is not derived from the equation of the force between two point charges. Since you are familiar with the equations for the relationships between point charges, however, you can conceptualize the above equation like this: Usually I think of the ...


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$PE = qV$ is usually used in parallel plates. $V = \frac{kQ}{r}$ is the electric potential at a point, r distance from the charge Q. So given the charge and the distance from a point, you use the second formula. $V = \frac{kQ}{r}$ was derived from $PE = \frac{kqQ}{r}$ and $PE = qV$. I hope you get the point I'm trying to make


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It's just a result of Gauss theorem applied in symmetry in this case surface area of sphere with charge placed at it's center. Which is 4 Pi R^2


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The Coulomb logarithm is a heuristic cutoff. For length scales beyond the Debye radius, electrons in a plasma see a smoothed electric field, not the $1/r$ potential of the neighboring electrons. Hence, when computing two-body scattering, for electrons with an impact parameter too far out, that particular charge will be screened and cut off. Thus, in any ...


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Let $A$ and $B$ be particles of different charge. In the world where $A$'s attract $A$'s and $B$'s attract $B$'s, while $A$'s repell $B$'s, you'll end up with one big $A$-cluster of particles and another far remover big $B$-cluster. On the other hand, if $A$'s attract $B$'s, you get an bigger $AB$ particle, arranged in space somehow, which can have ...



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