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AlonZ

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- which energy is it in E=hf and in lorentz invariant?

Hi there, I'm a bit confused about the E=hf equation for mass particle(f for frequency), and Lorentz Invariant (E^2 -p^2c^2=m^2c^4).

The question is, which energy is it? Total Energy- Kinetic plus Rest, or only kinetic energy.

Now, if it's total energy, then you get that a particle at rest (Ek=0) has frequency which can't be right by De-Broli's equation p=h/lambda.

And if it's only kinetic energy then I get the following: lambda=h/p=hv/mv^2--> 2Ek=mv^2=hv/lambda=hf (v for speed, f for freq).

so both ways don't add up for me, i have to be wrong somewhere, will be glad for your help.

Thanks a lot.

The question is, which energy is it? Total Energy- Kinetic plus Rest, or only kinetic energy.

Now, if it's total energy, then you get that a particle at rest (Ek=0) has frequency which can't be right by De-Broli's equation p=h/lambda.

And if it's only kinetic energy then I get the following: lambda=h/p=hv/mv^2--> 2Ek=mv^2=hv/lambda=hf (v for speed, f for freq).

so both ways don't add up for me, i have to be wrong somewhere, will be glad for your help.

Thanks a lot.

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