Abstract:
In this work the concept of energy and energy conservations in special relativity and generalized special relativity is discussed. The aim of the work is to incorporate potential energy in the energy relation. Some expressions conserves energy and other resembles Newtonian one, while other expressions combines Newtonian beside relativistic rest mass energy term. New special relativistic energy relation is obtained by using the formal definition of force. This expression includes mass energy beside potential energy, with energy conserved. The effect of friction on energy lost is found by using uncertainty relation. The special relativistic energy in the presence of friction is found. This relation is used to find new special relativistic quantum equation. Treating particles as vibrating string the mass is quantized.