Interesting problem - movement of dialectric

[JamesTheBond]

This is a problem was thinking about.

If I have a capacitor and fill it with a dialectric of some dialectric constant (the dialectric fits perfectly and is mounted via a frictionless bearing so it can move freely). How fast does it move?

 

[berkeman]

How fast does what move? Could you please be more specific and detailed about what you are thinking about?