Question

What's the Coulomb's law?

Answer 1

In layman's term: like charges don't attract while opposite charges doelectrostatic forces between point A( which is charged) and point B (which is also charged) are proportional to the charge of point A and point B. there is also something else about this  law that I don't quite remember.

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Here is the formula:

F = k x Q1 x Q2/d^2

What the formula means:

F=force between charges

Q1 and Q2= amount of charge

d=distance between these two charges

k= Coulombs constant (proportionally constant)

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I think that about covers it and hopefully this helped.

Answer 2

Coulomb's law states that if you place two particles of respective charges $q_1,q_2$ at a distance $d$ from each other, one will exert the following force on the other :

$\vec{F}=k\frac{q_1q_2}{d^2}\vec{u}$ where $\vec{u}$ is a unit vector from the first charge to the other and $k$ is a positive constant.

A direct consequence of this is that two charges of same sign repel each other, while two charges of opposite signs attract each other.