Modello per la risoluzione di un problema di fisica a livello di studenti universitari (Traduzione da The Physics Teacher, aprile 1990 a cura di C. Marchi Trevisi)

The exercise described in this article incorporates several features noteworthy of a physics problem and may serve as a model for creating other exercises. A wooden rod is free to rotate in a vertical plane around its upper end, with its lower end dipping into water. The problem consists in understanding its behaviour and determining its equilibrium angle with the vertical. First a qualitative, then a quantitative discussion are carried out. The calculations are finally confirmed experimentally through on-line measurements using the game-port of a PC.