How Does Coulomb's Law Inform Our Understanding of Electrostatic Forces?

AI Thread Summary
Coulomb's Law describes the electrostatic force between two charges, indicating that the force's magnitude is inversely proportional to the square of the distance separating them, and can be either attractive or repulsive. The discussion highlights the distinction between understanding what the law means and the information it provides. It emphasizes that describing the law inherently conveys information about the nature of electrostatic interactions. Additionally, there is a semantic note that clarifies the phrasing regarding the force acting on one charge due to another. The conversation also touches on the relationship between Coulomb's Law and Gauss's Law, suggesting that the latter is foundational and somewhat self-evident.
Sigma Rho
Messages
7
Reaction score
0
What information does this law give us?

This seems to be a different question to "what does this law mean?", which I could answer with "it describes the electrostatic force between two charges q1 and q2 separated by a distance r, the magnitude is inversely proportional to the square of the distance between them, and the force is either repulsive or attractive.. etc"

Does that answer the question, or is there some information that can be gotten from Coulomb's Law?

I'm pretty confused with this one!

Thanks
 
Physics news on Phys.org
Sigma Rho said:
What information does this law give us?

This seems to be a different question to "what does this law mean?", which I could answer with "it describes the electrostatic force...
You just answered your own question. Whenever you describe something, you provide information.
 
You can sort of wave your hands and say that, since it is an inverse square law, the interaction is mediated by isotropic emission of some particle. How? Because, as you get further away, the likelyhood of one of these particles colliding with a charge drops off as the square of the distance (which is justifiable with geometry, i.e., pre-physical).
 
Sigma Rho said:
"it describes the electrostatic force between two charges q1 and q2 separated by a distance r, the magnitude is inversely proportional to the square of the distance between them, and the force is either repulsive or attractive.. etc"

A comment on semantics:
In this context, the word "between" can be troublesome to some students, for example, when asked to draw the force.
A better phrase is the "electrostatic force on one charge due to the other".
 
What information does this law give us?

I could be off base here, but I see Coulomb's law as nothing more than a concequence of Gauss's law, so you should really be asking about that. The only problem with asking about the whys and hows of Gauss's law is it really isn't necessary, since its so obvious; akin to trying to extract information out of 1+1=2. You add a single thing with a single thing, and get two single things. An electric field diverges only from a place where charge exists. Same thing. It's tautological.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top