Recent content by SiggyYo

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    What is the divergence of a unit vector not in the r direction?

    Thank you chiro for the quick response. I am afraid I don't know what you mean. Wouldn't I just obtain the usual x=r\sin{\theta}\cos{\phi} y=r\sin{\theta}\sin{\phi} z=r\cos{\theta}? Also, I want \hat{k} to be a unit vector, which gives me r=1. How do I take this into account, when...
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    What is the divergence of a unit vector not in the r direction?

    Hi guys, I've run across a problem. In finding the potential energy between two electrical quadrupoles, I've come across the expression for the energy as follows: U_{Q}=\frac{3Q_{0}}{4r^{4}}\left[(\hat{k}\cdot \nabla)(5(\hat{k}\cdot \hat{r})^3-2(\hat{k}\cdot \hat{r})^2-(\hat{k}\cdot...
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    Energy of an electric quadrupole in an Electric Field

    What clem said about Franklin's "Classical Electromagnetism" are wise words in this context :P
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    How/when can I take a wave function and its complex conjugate as independent?

    For the last step in the derivation of the Gross-Pitaevskii equation, we have the following equation 0=\int \eta^*(gNh\phi+gN^2\phi^*\phi^2-N\mu\phi)\ dV+\int (N\phi^*h+gN^2(\phi^2)^*\phi-N\mu\phi^*)\eta\ dV, where \eta is an arbitrary function, g,N,\mu are constants, h is the hamiltonian for...
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    How to find flux through certain sides of a surface with divergence theorem.

    Homework Statement Given a vector field \textbf{F} and a composite (with this I mean cuboids, cylinders, etc. and not spheres for example) surface S, how do I calculate the flux through only some of the sides of S? I am interested in a general way to do this, but right now I am struggling with...
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