I got alittle confused on something... say an elevator is moving downward and its speed decreases. If you are drawing a FBD of a block inside the elevator, there are only two forces acting on the block, normal force from the elevator floor and weight force. But since elevator is decreasing in speed, netforce does not equal zero. Which vector, if any, should be longer than the other. Weight or Normal? or are they suppose to be equal? I guess if you were drawing a FBD of the elevator itself, i'd be pretty easy, but i can seem to figure this one out. help please.