Answer:
,
and
.
Explanation:
Three balls are shown in figure having charge . The middle ball,
, is positively charged having charge
, and the remaining two outside balls,
and
, are negatively charged having charged
as shown.
and
cm as B is the mid-point of AC.
Let and
From Coulomb's law, the magnitude of the force, , between two point charges having magnitudes
, separated by distance,
, is
where, is the permittivity of free space and
in SI units.
This force is repulsive for the same nature of charges and attractive for the different nature of charges.
Now, Using equations(i),
(a) The magnitude of attraction force between balls A and B is
(a) The magnitude of the repulsive force between balls A and C is
(c) The magnitude of the net force, , on the outside of the ball is,
