Physicists are also people and can appreciate nice wording, politeness and paradoxes. I am asking specifically about this imprecise question which appears amusing because it is not strictly defined. The actual question in that case is what am I missing in my description of the system, not how does it work.
Should we push to straighten out the question? As-is it leaves ample room for nice dissertations on the laws of physics (already present in the answers, expect more to come). If reworked to be clear, the question will become its own answer and the correct bare-bones answer will look almost trivial, not at all noteworthy. Do we foster amusing site content generation so that visitors have more prose (and poetry) to read, or trim it down to formula for formula, measurement for measurement?