Abstract
In Einstein's theory of special relativity, the relativistic momentum is concerned with the motion of a particle of relativistic mass whose velocity approaches the speed of light, but not equal to the speed of the light. An electromagnetic photon is a massless particle and its momentum is concerned with the motion of the massless photon whose velocity is equal to the speed of light. This paper focuses on the momentum of massless photon and a particle with relativistic mass.



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