> in relation to which of your speeds? > the original walking speed? Sure, in which case the answer is "not enough information." Same applies to falling speed, in case you decided to jump. > the running speed? See Mike's solution. > or the standing there calculating where the trains going to hit you speed? For standing speed (velocity=0), I would have accepted either of the following answers: a) the train is moving infinitely faster than me, or b) divide by zero error followed by a program crash. -Sean