A user writes:
Four particles with charges +5.00 micro Couloumbs, +3.00 micro Couloumbs,
3.00 micro Couloumbs and -5.00 micro Couloumbs are placed at corners of a
2.00m X 2.00m square.
(a) Determine the electric potential at the center of the square, assuming
zero potential at infinity.
(b) If one of the +3.00 micro Couloumb charges is replaced by a +4.00
micro Couloumb charge, what is the electric potential at the squares
center?