Demos: 1N-08 Magnetic Accelerator Paradox
Start by moving a single ball to a higher point on the track. Release it so it will collide with the remaining balls stationed on the lowest part of the track. Nothing unusual happens as expected because of the Conservation of Momentum/Energy Principles. Now repeat, but replace the ball that will come in contact with the raised ball with a magnetized ball and watch what happens. The last ball in the track should accelerate and leave the track. The reason for the different behaviors is this: as the raised ball moves down the track it is gaining kinetic energy from two sources, gravity and the magnetized ball resting at the lowest part of the track.