I Why Does a Charged Box Exhibit Higher Inertia Due to Mass-Energy Equivalence?

[andreabalestrero]

A charged, metallic box has an energy content higher than an uncharged box, due to the energy stored in the electric field (which is equal to the work that has to be done to bring the charges from "infinity" to the surface of the box). So, due to the mass-energy equivalence, a charge box has a higher rest mass, and it will offer a higher resistance when accelerated. Is there a thought experiment that could explain why a charged box is harder to accelerate?

 

[PeterDonis]

Is there a thought experiment that could explain why a charged box is harder to accelerate?

Didn't you just describe one?

 

[andreabalestrero]

Actually, I was thinking something like that accelerating a charged box will produce EM radiation, and somehow the outgoing momentum of the radiation results in a force to be balanced to push the box

 

[Vanadium 50]

This was attempted in the 19th century. It did not work out. You get 4/3 = 1 and similar nonsense.

You cannot separate the charge from the field and say "this much mass is over here and that much mass is over there", just as you can't allocate the mass of a system of photons to each individual, yet massless, photon.