Hi. I have one general question and one specific question (which is related by example.) Specific: If I am sitting in a chair with wheels and I push off against a wall, I accelerate. But the force was not applied through any distance. Did I do any work? (I know that an impulse was applied, for I pushed off against the wall.) If so, how? General: Is it possible for work to be done without applying an impulse, or vice-versa? (Note: I'm pretty confident that work cannot be done without an impulse; for I do not know of any way in which an object can travel through a distance in no time. But the "specific" question makes me ask whether the converse is true.) Thank you.