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I am trying to teach myself quantum mechanics so take it easy on me.

In 1905, Einstein proposed that light is made of photons and that each photon carries energy E = hf (f is frequency) and momentum p = h/w (where w is wavelength)

My question is how did he go from the definition of momentum which is mass times velocity to the aforementioned p = h/w. Is there an easy straightforward answer to this or is it something derived from classical thermodynamics?

thanks

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# Momentum of a photon and Einstein

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