What Determines the Force on a Charge?

[Ashley1nOnly]

Homework Statement

I wanted to know how the charges knew their distance from each other.

Homework Equations

f=k(q1*q2)/r^2

The Attempt at a Solution

I think it has something to do with the electric field lines that each charge outputs.
But I'm curious as to what these lines do once they hit another field line. Do they send information back and let the charge know that there is a like or opposite charge a some position?
opposite = attract
like=repel
I know f=qE
E=(kq)/r
Why does the distance determine the force on a charge and not something else?

 

[cnh1995]

E=(kq)/r²

Why does the distance determine the force on a charge and not something else?

Permittivity also plays a role in determining the force. Basically, it's the electric field that varies with distance as 1/r². Hence, the force depends on the separation as 1/r².