The fact that all of the magnets took longer than the non-magnetic ball to travel through the tube illustrates that the magnets' interactions with the copper did in fact slow them down.

As you can see, there is no blatant, direct correlation between the strength of the magnetic field a magnet creates and the time it takes that magnet to go down through the tube. The most telling discrepancy in our results is that between the neodymium fragment magnets and the stout magnet. As pictured in the chart above, the two magnets have the same magnetism and approximately the same mass. The only difference between the two magnets was the shape -- the stout magnet had more close contact with the surface of the tube because of its cylindrical shape than the neodymium fragments did. Similarly, the rectangular magnet fell down the tube almost five times as fast as the long magnet even though their magnetic fields are approximately the same and their masses are in the same ballpark.

The instant a magnet is dropped into a tube, an electrical current is induced that flows down the copper tube. This electrical current creates a magnetic field in the opposite direction that interacts with the magnet. The fields cause the magnet to be pulled towards the copper tube and creates resistance. This resistance, however, depends on the shape and mass of the magnet. The neodymium magnet was very thin and had little contact with the copper tube, so it fell relatively quickly. The stout magnet was just shy of being the diameter of the copper tube, so it had plenty of contact that caused significant resistance in its fall. Although the cow magnet had a large surface area that was close to the tube, it was very heavy, so the induced magnetic field was not strong enough to slow it down much. The same can be said for the other longer magnets.