The Development of Coulomb's Law

  • Thread starter Thread starter BelaLuna
  • Start date Start date
  • Tags Tags
    Coulomb's law Law
AI Thread Summary
Coulomb developed his law by observing the force between charged objects, noting that it is proportional to the product of their charges and inversely proportional to the square of the distance between them. He utilized a torsion balance for his measurements, but the exact method he used to determine the constant "k" remains unclear. The discussions highlight that Coulomb's work predates the contributions of later physicists like Gauss and Maxwell, who further developed the theoretical framework of electrostatics. While some questions about Coulomb's methodology persist, it is acknowledged that he measured forces between known charges to derive his findings. The conversation reflects a quest for clarity on the historical development of Coulomb's Law and its constants.
BelaLuna
Messages
2
Reaction score
0
Hello, I am new here. I have a question that I cannot seem to find an answer to and is beginning to bother me in the worst way.
I was researching to find out how Coulomb developed the formula that is used today (since I do not have the programme, I shall not even attempt to write it) and found that not one source could give me a straight-forward answer. It simply said that he thought the relationship was caused by two different fluids and that the unit coulomb and Coulomb's Law is named after him. This is leading me to believe that someone else had continued upon the theory, fully explained the relationship, and developed the formula. And if this is so, who? Who developed it?
This may seem silly, but it is frustrating after reading at least eleven different articles of the subject and not being able to find an answer to a relatively simple question. Does anyone have an idea as to who this person may be? Or am I gravely mistaken in thinking that there is another person?

(if this is a double post, i offer my sincerest of apologies, but my internet is acting rather strange tonight and am not sure if this came through)
 
Physics news on Phys.org
torsion balance

From what i know Coloumb just noted the simple fact that the magnitude of the force one charged object exerts on another (like conducting spheres) is proportional to the amount of charge on both objects and inversly proportional to the distance between them squared.

http://en.wikipedia.org/wiki/Image:Bcoulomb.png

above is a link to a drawing of the torsion balance he used to make his measurements.
 
Did some more research and had that question answered, but I still cannot find how Coulomb found the constant "k." It is a queer number and must have been found somehow, but I can't find how he did it. The torsian balance was used, of this I am sure, but how?
 
The electrostatic can be found by:

k_c = \frac{1} {4 \pi \epsilon_0}

where \epsilon_0 is the permittivity of free space and is found by:

\epsilon_0 = \frac {1} {c^2 \mu_0}
 
Last edited:
BelaLuna said:
Did some more research and had that question answered, but I still cannot find how Coulomb found the constant "k." It is a queer number and must have been found somehow, but I can't find how he did it. The torsian balance was used, of this I am sure, but how?

He simply measured the force for a known pair of charges and a known separation.

To Ranger: I'm not sure Couloumb had the luxury of using those equations, since Couloumbs work preceded that of Gauss and Maxwell! :smile:

Claude.
 
It may be shown from the equations of electromagnetism, by James Clerk Maxwell in the 1860’s, that the speed of light in the vacuum of free space is related to electric permittivity (ϵ) and magnetic permeability (μ) by the equation: c=1/√( μ ϵ ) . This value is a constant for the vacuum of free space and is independent of the motion of the observer. It was this fact, in part, that led Albert Einstein to Special Relativity.
Back
Top