OK this kind of has to do with physics, but more of what happnes when you squash something i suppose. Anyways my dad told me this riddle and when i gave up he said he forgot the answer and it has been bugging me for a while. One thing traveling on a straight path must come to a stop before traveling in the opposite direction. If a man is running on a train track at lwt's say 1mph, and a train is coming at him at 100mph, when they collide, does he stop the train? I am guessing that the air around him would kind of slow him down to zero as it gets pushed out to the sides, but what if it was in a vaccum (if he could survive)?