What Are the Correct Units for the Larmor Formula?

AI Thread Summary
The Larmor formula is expressed as P = (μ₀ q² a²) / (6π c), where the user initially calculated the units to be [kg m² s⁻¹], questioning if it should be [kg m² s⁻³] for watts. The user detailed the SI units for each variable: μ₀ as N/A², q² as C², a² as m² s⁻², and c as m s⁻¹. Upon reevaluation, the user realized that the units of acceleration were incorrectly noted as m/s instead of m/s², leading to a correction in the units of a² to m²/s⁴. This correction clarified the dimensional analysis, resolving the initial confusion about the formula's validity. The discussion highlights the importance of careful unit analysis in physics.
bdforbes
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The Larmor formula is:

P=\frac{\mu_0 q^2 a^2}{6\pi c}

When I checked the units of this, I got [kg m^2 s^-1]. If it is in watts, shouldn't it be [kg m^2 s^-3]? I was pretty thorough in putting everything in SI units.

\mu_0 is N/A^2 or kg m s^-2 A^-2.
q^2 is C^2 or A^2 s^2
a^2 is m^2 s^-2
c is m s^-1

Have I made a stupid error, or is this just the wrong way of doing the dimensional analysis?

This is not homework.
 
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I don't think the formula is right.

edit: Never mind. :P
 
Last edited:
The units of acceleration are m/s^2 not m/s, so the units of a^2 are [/itex]m^2/s^4[/itex] not [/itex]m^2/s^2[/itex].
 
Stupid error it is then, thanks :P. You'd think after 4 years of uni I might be able to get that one right...
 
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