# Homework Help: Electric potential and electric potential energy question

1. Nov 28, 2005

### firebug

the question, from the Nelson Physics 12 texbook, is :

Three charges are placed at the corners of an equilateral triangle with sides of lenght 2.0 m. the charges, in clockwise starting at the top of the triangle are (c being coulombs) +4.0^-6 c, +2.0^-6 c, and -4.0^-6 c. a) calculate the total electric potential energy of the group of charges. b) determine the electric potential at the midpoint of each side of the triangle.

Just curious, if anyone could inform me of the steps of how to solve, that would be nice, i can take it from there. thanks in advance.

-firebug

2. Nov 29, 2005

### mezarashi

The potential can be calculated by finding the work needed to bring the 3 charges into the said configuration (from infinity). Start with one charge, bring in the second, then the third.

To determine electric potential, you can once again use basic principles and find the work needed to bring a test charge to the designated place. The voltage is then this work divided by the test charge. You will find that the superposition of the V = kq/r equation will generally apply however.