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syang9
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Homework Statement
In the SI system, the energy density of the electric and magnetic fields is:
[tex]
u = \frac {\epsilon_{0} E^{2}}{2} + \frac{B^{2}}{2 \mu_{0}}
[/tex]
From the equation above, derive an exact expression for the energy density [tex] U [/tex] in the Gaussian system of units.
The Attempt at a Solution
Obviously the energy densities must be proportional to the squares of the intensities. So, I can start with
[tex] U_{tot} = E^{2} + B^{2} [/tex]
I know that cgs eliminates the need for epsilon and mu, but I haven't a clue as to how to start from that one equation. Previously in the assignment, my instructor mentions that in Coulomb's law, [tex] \epsilon_{0} [/tex] has been eliminated by redefining the electric charge in the Coulomb law ([tex] \frac{q_{1} q_{2}}{4 \pi \epsilon_{0}} \rightarrow q_{1} q_{2} [/tex]) and [tex] \mu_{0} [/tex] has been eliminated by using the speed of light: [tex] \mu_{0} \rightarrow \frac{1}{c^{2} \epsilon_{0}} [/tex].
However I haven't a clue as to how to proceed with this information. Any hints would be great! Thanks in advance.
Stephen