We enjoyed this at Whinlatter. It is an ancient type of water pump and such a wonderful technology. So how to do a thorough-going Physics analysis? The weight of the water holds it in the bottom of each section. You turn the handle and the walls of the screw apply a centripetal force to the water, pushing inwards on it. It is a complex example of centripetal motion because the water itself does not spin round. It has inertia so it tries to stay where it is and I suppose that the metal walls slide underneath it. The kinetic energy put in by you turning the handle is transformed into gravitational potential energy as the water finds itself in the next level of the screw. That's an outline of the ideas going through my head. I'm not yet convinced that I've put the parts together in a logical and forceful way.
