-3

I have done some calculations to get relativistic mass and rest mass of a photon.
Are my calculations correct?
If Yes how much significance do they really have in physics?

This image has calculations for rest mass i.e m0

This image has calculations for relativistic mass

enter image description here

Sorry for I have written proton instead of photon in calculations . Hope you understand.

Java Rookie
  • 153

1 Answers1

2

That would be true... if the photon did have $m_0$, but it actually doesn't.

Check that it makes no sense to have a particle with infinite mass. Instead, if you write $m_0=0$, then you get $0/0$, which is undetermined.

And you solve that using the other great formula. It's actually one of the key formulas of Sp.Rel.:

$E^2 =p^2 c^2 +m_o^2c^4$

For a photon, it's just $E^2 =p^2 c^2$ or $E=pc$, which does make sense. The energy is only due to momentum, and not due to rest mass. It depends on the frequency because $p=\hbar k$.

FGSUZ
  • 8,573