Year: 2005 Pages: 2

_{W}= m

_{o}- qV/3c

^{2}for a charge q placed in a region of Coulomb's potential V.

In page 161 of Mikhailov states: ?So, if q and V have same (opposite) signs there is a decrease (increase) of the particle's effective mass.? Then, for q = ?e and V = k(Q/R) > 0, we get a mass increase yielding m = m_{o} + eV/3c^{2} > m_{o}.

We remember now that also Einstein's mass-energy equivalence, m_{E} = Energy/c^{2}, allows us to predict the electron mass-electrostatic potential dependence, of the same order of magnitude but opposite in sign. As a matter of fact, we have described the electronic mass defect taking place in the atomic electron. Let us consider an electron inside a positively charged spherical shell of charge Q, radius R producing a potential V = k(Q/R) > 0. The mutual electrostatic potential energy is ?eV < 0, so that a positive work must be supplied to carry the electron to infinite.