2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84686Simple expression for self-force acting on radiating rigid charged ball is derived (Sommerfeld ball). It is shown that appropriate delayed equation of motion has solutions in general differ from that for Sommerfeld sphere - there are no "radiationless" solutions, but there are oscillating without damping solutions though self-force has nonzero value.LATEXClassical PhysicsMathematical Physicstext