Electric Potential Energy
- Example: what is the potential energy of this collection of charges?
- What is the significance of the minus sign?
A negative amount of work was required to bring these charges from infinity to where they are now. ie the attractive forces between the charges are larger than the repulsive ones.
http://wug.physics.uiuc.edu/courses/phys112/fall97/acts/lect07/act07a/sld001.htm