I have a question about photons and relativistic momentum. According to my Physics text (Serway & Beichner), the energy of a partle with zero mass, such as a photon, can be related by E[tex]^{}2[/tex]=p[tex]^{}2[/tex]c[tex]^{}2[/tex]+(mc[tex]^{}2[/tex])[tex]^{}2[/tex]. m=0 so the expression becomes E=pc. Since relativistic momentum is p=mu/[tex]\sqrt{}1(-u2^{}[/tex]/c[tex]^{}2[/tex]) and m=0 for a photon, how is there any momentum and thus energy?(adsbygoogle = window.adsbygoogle || []).push({});

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# Relativistic momentum and photons

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