what is the potential energy of 4 point charges each of value Q at the corners of a square of side length a.

6 answers

potential energy is a function of distance from the charges. Where do you want it?
at the centre or one of corners
Well, at a corner it is infinite since we have that division by zero problem when r = 0

at the middle, find the potential of one of them at a distance of (a/2)sqrt 2

The neat thing about potentials is that they add like scalars. Just multiply by 4.
so it will be kq(4Q/a/2)
Suspect so :)
4kqq/r^2