What happens if you put your head in the Geneva water jet? An inquiry-based physics activity exploring fluid dynamics

Abstract

We describe a physics education activity for third-year Bachelor students, inspired by a humorous question about the Geneva water jet. The exercise engages students in key scientific practices: reformulating everyday questions in scientific terms, constructing simplified models, performing semi-quantitative estimations, and comparing alternative solution methods. Students explore approaches based on Bernoulli principle and a power analysis, revealing consistent results when assumptions are carefully considered. The activity emphasizes critical reasoning, including identifying relevant data, making approximations, and applying energy and mass conservation to incompressible fluids. It also fosters metacognitive skills and higher-order thinking (HOT), illustrating the universality of fundamental physical principles across diverse phenomena. By situating the task in a relatable, real-world context, the activity motivates students while exposing them to problem-solving challenges rarely encountered in traditional instruction, such as Fermi-type estimation and cross-context knowledge transfer.