In this paper we present a new experiment on superconductivity, designed for university
undergraduate students, based on the high-speed video analysis of a magnet falling through a ceramic
superconducting cylinder ( T c = 110 K). The use of an Atwood’s machine allows us to vary the
magnet’s speed and acceleration during its interaction with the superconductor. In this way, we
highlight the existence of two interaction regimes: for low crossing energy, the magnet is levitated
by the superconductor after a transient oscillatory damping; for higher crossing energy, the magnet
passes through the superconducting cylinder. The use of a commercial-grade high speed imaging
system, together with video analysis performed using the Tracker software, allows us to attain a
good precision in space and time measurements. Four sensing coils, mounted inside and outside the
superconducting cylinder, allow us to study the magnetic flux variations in connection with the
magnet…