Hi, So. I'm preparing for a test, and a problem I was given in order to prepare for this test is confusing me to no end. It's very unlike the rest of the problems I was given, and I'm not quite sure how to solve it. http://www.synthdriven.com/images/deletable/23-4.jpg [Broken] I'm on a chapter dealing with what exactly electric potential is, and given this information, I'm not quite sure what to do. I'm to find the electric potential, V, across those plates that'll hold the droplet of oil motionless. However, I have no charge or value for capacitance. ...It tells me that there are "5 electronic charges". However, I don't have a value for a single one. Does the horizontal component of electric force have to be equivalent to mg or something? Any tips or ideas?