(2 68)
W
Q
C
Q
C
Q
Q
C
Q
Q
=
′
=
′
=
∫
0
2
0
2
1
2
2
δ
’
We can write the final result, in different ways
2
2
1
1
2
2
2
Q
W
CV
QV
C
=
=
=
(2 69)
Since electrostatic force is conservative, this work is stored in the form
of potential energy of the system For the same reason, the final result for
potential energy [Eq