This is a very interesting question you propose, but it is not an original one. This question has been around for centuries and has in more recent times been applied to particle physics since it makes more sense to talk about this in terms of fundamental particles vice huge quantities of matter. It is not clear whether you are interested in a philosophical discussion on this topic or an actual quantified measurement. If it is an exact value you want, you can forget it because there is not one. Werner Heisenberg provided an excellent yet somewhat debated solution on why you can't answer this question (and similar ones) precisely in 1927. His notion is now known as the "Heisenberg Uncertainty Principle" which basically states: it is fundamentally impossible to make simultaneous measurements of particle's position and speed with infinite accuracy. I personally can not do justice to this principle, so I won't even try to explain it, however I suggest you might find this an excellent reference to study in order to put your mind at ease (or not). Hope this helps.