(solution) Many subatomic particles (including the electron) behave as if

(solution) Many subatomic particles (including the electron) behave as if

Many subatomic particles (including the electron) behave as if they were spinning around their axis. Empirically, the electron has a spin angular momentum h/4?, where is Planck?s constant. A simplistic model imagines the electron to be a spinning uniform ball. Other measurements indicate that if the electron really is a ball, its radius is less than 10?8m. Show that if the simplistic model were true, a point on the electron?s equator would be moving much faster than light. (A more sophisticated quantum-mechanical model of electron spin avoids this paradox.)