
9–66 Electricity and Magnetism
V (P) =
N
X
i=1
V
i
(P) =
N
X
i=1
k ∆q
i
|~r
i
|
i
P
+
~r
i
FIGURE 9.4 Obtaining the Electrostatic Potential outside a Distribution of Charge
Electrostatic Potential Energy and Distributions of Charge
As has become customary, the partition, compute, and sum method is employed to deal
with continuous distributions of charge. The distributed charge is partitioned into N small
charge elements, ∆q
i
, as shown in Figure 9.4. The contribution to the potential at the field
point P due to each charge element, treated as a point charge, is computed. These are
summed to yield the net potential at P.
Infinitely refining the partition, via the simultaneous ...