I was discussing with my colleagues why it feels easier to walk up an escalator when it is moving. My natural assumption was that the movement of the escalator imparts some extra acceleration on the rider that helps to move up the stairs. But my colleagues insisted that this was nonsense, and that the affect is purely psychological (i.e. it just seems easier).
We actually came up with three contradictory hypotheses, and I'm not sure which is right: 1. The escalator is constantly accelerating the rider since without constant acceleration the body wouldn't be able to counteract the force of gravity (i.e. my theory). 2. The rider is not accelerating since no acceleration is needed to maintain a constant velocity. 3. The acceleration of the escalator actually makes it harder to get to the next step since it pushes the rider against the current step.
Which of these is correct?