..no, wait, I think I actually got this. Once I place the -q charge under the plane, the problem becomes equivalent to this:
[PLAIN]http://img189.imageshack.us/img189/6430/spherel.png
, and then I just need to place charges q' and -q' symmetrically to the z=0 plane so that the potential on...
1J is the energy exerted by a force of 1N thaat moves an object by 1m. The force in this case is 10N and the distance is 50m(0.5at^2=100/2), so 500J seems fine.
Homework Statement
http://img532.imageshack.us/img532/3751/39842434.png
Find the potential in all space for this configuration.
Homework Equations
..basic electrostatics stuff, I guess.
The Attempt at a Solution
I can easily cancel the whole z=0 plane by placing a charge of -q...