Choose one pipe and move the magnet that is set on the pipe upward. Drop the magnet and observe its motion. Conduct that experiment with different pipes and compare the results. Turn the frame with pipes to place all magnets up at once. Observe the magnets’ race.
How does it work
Falling magnet induces so-called eddy currents in the pipes. These currents create a magnetic field that opposes the field of the magnet. As a result of interaction between magnetic fields of the magnet and of eddy currents, the magnet does not fall freely. The effect of slowing down the fall is proportional to the magnitude of eddy currents. Magnitude of eddy currents depends on the electrical conductivity of a particular pipe. The pipe are made of: copper, aluminium, brass and stainless steel.
Why is this happening
Eddy currents are created due to lectromagnetic induction. This phenomenon, discovered in 1831 by English physicist Michael Faraday, is the most used form for generating electricity.