there is a +q and -q on the x-axis. the +q is L/2 in the negative direction and the -q is L/2 in the positive directions. the distance between the two charges is L. there is a test charge P on the y-axis a distance r from both charges.
we had to find the electric energy stored in the dipole...
I think it should be 1/2 ln(x^2 + 4) - arctan(x/2). Take a look at the second integral; when you factor out the 4 in the denominator it will cancel with the 4 in the numerator so it should not be -2arctan(x/2) but just -arctan(x/2).
Also don't forget your limits of integration
Nevermind I am an idiot. It is milliCoulombs not micro. So once i took -q3 into account like you said i got the right answer which is -62402.4J. Thanks for the help.
My brain does not work to well so late at night :)
Ok, I reworked the problem with mC this time and took into account the -q3 but still get the wrong answer. I thought you were supposed to take the magnitude of the charges so I worked it that way but get a different but wrong answer.
edit: I edited the mC in my second post to be correct. I did...
Homework Statement
Three charges are at rest on the z-axis, q1 = 2 mC at z = 0 m, q2 = 0.6 mC at z = 1 m, and q3 = -1.5 mC at z = -0.4 m. What is the potential energy of this system?
Homework Equations
The Attempt at a Solution
Here is what i tried: K( (q1*q2)/r +...