I was watching a Khan Academy video (here) on electric potential energy (not Voltage.) Here was the problem:
There is an infinitely extending positively charged plane (uniform.) The charged plane has a positive electric field with 5 N/C (Newtons per Coulomb.)
Electric Potential Energy is the amount of energy it would take to move an electron x distance in y direction.
F = Eq (where E is the electric field, q is the amount of charge, and f is the force.)
Here's what I don't understand.
Sal says that the amount of force it would take to move the electron is E*q. In this case 10 N, (2C * 5N/C.) And that the amount of work to move 2 C of charge against this electric field would be 10N*3M = 30NM = 30 Joules (J). Yet how could the electrons possibly accelerate towards the 3M if the electric field pushing the electron away and the electric field pushing the electron toward the electric field are the same. (They are both 5 N/C.) Shouldn't the electron just say where it is? And if that is the case, since W = Fd and d is 0, the work is 0. And if the work is zero then the potential energy would also be zero.
What am I misunderstanding?
W = Fd
F = Eq
The Attempt at a Solution
I've searched my book, Practical Electronics for Inventors as well as The Physics Classroom and Wikipedia for answers. So far I have had no luck.
Thank you so much for your help