The animation begins blank. Then a piece of carbon paper appears, viewed from the side, at the bottom of the image. Then a piece of newsprint appears above it. Then the puck appears. It is drawn as a cutaway with a flexible tube extending down from the top of the screen to just above the newsprint. On either side of the tube, the puck extends out so that its surface area is increased. Then arrows show how the air flows down the tube and out between the newsprint and the extended sides of the puck. The pressure of the air lifts the puck off the paper, where it hovers with very little friction. Then an electrode at the end of a chain is dropped down inside the pipe. Electrical pulses travel along the chain and into the electrode where they leap across the gap to the table, through the newsprint and the carbon paper. The result is a dot of carbon on the newsprint. If the puck is in motion, the dots will leave a record of its path. This is shown in the next image in the animation in which the puck cutaway is removed and a track of dots is shown. The dots are a record of the air table pendulum. At the start, the puck moves slowly so the dots are tightly packed together. But, as the puck accelerates down the table the dots get further and further apart. However, once the puck starts to swing back up, its speed decreases and the dots become closer and closer. The final result is that the path of dots is symmetric on either side of the low point in the curve. The low point is labelled (Ek)maximum, maximum kinetic energy, and one of the high points is labelled (Ep)maximum, maximum potential energy.