STUDY ON MAGNET CLIMBING MOTION ON FERROMAGNETIC CYLINDERS

This paper investigates the intriguing climbing motion of magnets proposed in Problem 4 of IYPT 2025. The results show that the climbing motion originates from periodic stick-slip interactions. A theoretical model based on the magnetic charge method is established, and an experimental apparatus is constructed to systematically study the effects of the parameters of neodymium magnets and ferromagnetic rods. The results show that, within the critical range, the climbing velocity first decreases and then increases with increasing magnet length and ferromagnetic rod diameter. The climbing velocity decreases as the remanence of the magnet increases. In addition, as the distance between the constraint point and the magnet or the magnet diameter increases, the climbing velocity first increases and then decreases. The theoretical predictions agree well with the experimental results, providing a clear explanation of the physical mechanism and main influencing factors of the climbing motion.