if you were to look at a "freeze frame" of time (i.e. a movie that's been paused) and you saw a baseball in the air. how would you know that it had a velocity?? i mean, a baseball is a collection of atoms. how would you know, just by observing it, that it has a velocity (and what velocity? can you tell?) At each moment in time, each object must have an "instantaneous velocity". How do you explain that in terms of the atomic scale??