Originally Posted by CyberSEO

This depends. If the elevator is falling with an acceleration of gravity, you won't be able to jump, because you will be in zero a gravity. If it's falling slower than that (because of friction and air resistance), you will be able to jump and compensate the difference between your jump speed and the speed of еру falling elevator. So you can compensate it in case if the elevator has felt form about one meter (you can't jump higher if you are not a trained sportsman). Course in case if the elevator has felt from 10 meters (~ 3 floors), your jump won't help you at all... This is obvious, isn't it?