## A New Look at Energy Sample Problem

(It) What is the total energy E of a 2.53 MeV electron? SOLUTION:he KeyIdea here is that, from Eq, 38-44, the total energy E is the sum of the electron’s mass energy (or rest energy) IIIC~ and its kinetic energy: E = 0.511 MeV + 2.53 MeV =»3.04 MeV. (Answer) ib) What is the magnitude …