Imagine a charged particle suspended between 2 horizontal magnetic plates, which create a uniform magnetic field. Now instantaneously, the particle is accelerated to velocity $v$. By my understanding, the particle will now start doing uniform circular motion, due to the Lorentz force.
However, what if the magnetic field is moving, instead of the charged particle? Instead of the particle being accelerated, now the magnetic plates are instantly accelerated to velocity $v$.
What happens to the charged particle?
- Does it now undergo that same uniform circular motion (in the magnetic plates' reference frame), and in doing so, does it "keep up" with the magnetic plates?
- Does it get accelerated by the Lorentz force, but eventually falls out of the magnetic field?
If 1 is what happens, how did the particle gain kinetic energy? It went from stationary to moving, but I was taught that magnetic field cannot do work on charged particles. So then what did the work on the particle?
If 2 is what happens, then why is this scenario any different than accelerating the particle instead of the plates? Shouldn't those two scenarios be the same in the magnetic plates' reference frame?