If the electron were a classical solid sphere, with radius

(the so-called classical electron radius, obtained by assuming the electron’s mass is attributable to energy stored in its electric field, via the Einstein formula E = mc²), and its angular momentum is (1/2) ћ, then how fast (in m/s) would a point on the “equator” be moving? Does this model make sense? (Actually, the radius of the electron is known experimentally to be much less than r_c, but this only makes matters worse.)

rc = e 4 qmc" (4.138)