Now, if the separation between A and B is halved, the magnitude
of the electrostatic force on each is
′ =
′
=
′ =
F
q
q
r
rqq
F
41
2
2
2
41
0
2
0
2
π
π
ε
ε
( / )(
( / )/ )
(
)
Thus the electrostatic force on A, due to B, remains unaltered 1 6  FORCES BETWEEN MULTIPLE CHARGES
The mutual electric force between two charges is given by
Coulomb’s law How to calculate the force on a charge where
there are not one but several charges around