In reply to Stefan Israelsson Tampe's message of Mon, 1 May 2023 17:52:27 +0200: Hi Stefan,

You write:- "Now the total amount of energy is 2u if we assume equal amount of electrical energy as magnetic energy, hence if we integrate. F = Utot/va But according to special relativity we have, Utot = mc So, F = mc/va No put v = c we see, F = ma" However I think Utot = mc^2 (not mc) and setting v=c => F = m/a not m*a If the we instead start with Utot = mc^2 we get F = mc^2/va which after substituting c for v => F = mc/a. ...so how does c/a magically become a? ;) Cloud storage:- Unsafe, Slow, Expensive ...pick any three.