Imagine if you had piston in a cylinder. For purposes of this experiment ignore the effects of gravity and friction. One end of the cylinder is capped. On the interior face of this capped end, are 4 magnets around it's diameter. The pattern is -, +, -, +. The piston has an identical aligned pattern of magnets on its face except , -, -, -, -. Two of the magnets will be attractive, and two of them repellent. All the magnets are equal strength. Wouldn't the net force between the cylinder and the piston be 0? When they come in contact, how will they behave? First if both the cylinder and piston cannot rotate relative to each other, and second if could spin relative to each other?