Stuck on this dimensional analysis question.

vendredi 29 novembre 2013

1. The problem statement, all variables and given/known data

The total power radiated by an oscillating electric dipole is a function of the oscillation frequency ω, the dipole moment p(=Qd, where ±Q is the charge at each end of the dipole and d is the distance between charges), the speed of light c and the permittivity of free space ε0. Apply dimensional analysis to find the form of this function. Hence find the ratio of the power emitted by the same dipole at frequencies ω and 2ω



2. Relevant equations







3. The attempt at a solution

I started off by writing out the units and trying to find the powers, this left me with:

J/s ∝ (Hz)A (Qm)B (m/s)C (F/m)D

My first thought was that C=1, so that there is s-1 on each side.

Then I thought that D=2 so that the metres cancel out.

Then I'm left with J ∝ (Hz)A Q F2 /s

And now I'm completely stuck :(

Any help appreciated, thanks.

1. The problem statement, all variables and given/known data







2. Relevant equations







3. The attempt at a solution






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