Electric Potential Energy Due to Multiple Charges:

A Numerical Example

That's all there is to it. Now let's try an example.

These charges are already in place:

How much work is required to bring in an additional charge q? This additional charge q is located at x = 0.2 m, y = 0.1 m. How much work is required to move this charge q in from infinity to this location?

That is, What is the PE of charge q because the other Q's are there?

Find the PE for the new charge q and each other charge Q; then add up the sum (ordinary, scalar addition).

Electric Potential Engergy -- like any form of Potential Energy or any form of Energy or any form of work -- is a scalar. There is do direction associated with work or energy. The sum of the Potential Energy terms involves just an ordinary scalar equation. That's easy; make use of it.

El PE Due to Multiple Charges


Return to Ch 17, Electrostatics & Electric Energy
(c) Doug Davis, 2000; all rights reserved