I have now worked out all values for the quadrupole matrix, I just need to calculate what Qzz is. If anyone can help that would be really useful. Also I realized I made a mistake above, cylinrical symmetry means that it is dependent only z only.
Homework Statement
Show that, if a charge distribution has cylindrical symmetry, then knowing the value
of Qzz allows you to determine the entire quadrupole moment matrix.
Homework Equations
Tr Q=0, ie Qxx+Qyy+Qzz=0
The Attempt at a Solution
Because of the cylindrical...
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...