- #1
Josephk1508
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Homework Statement
Four point charges: q at a^z; q at -a^z; -q at a^y and -q at -a^y
where ^z and ^y are the unit vectors along the z and y axes.
Homework Equations
Find the approximate expression (i.e. calculate the first non-zero term in the multipole expansion) for the electrostatic potential at large distances.
The Attempt at a Solution
So far I have worked that the monople and dipole moment is zero. So i realize I need to move onto the quadrupole moment. Which is what I'm struggling with.
The formula is Qij= Ʃ(i) qi (3RiRj-R^2(δij))
Any help would be appreciated.