Abstract: The mean free path is a fundamental concept in physics that reveals the statistical nature of microscopic particle motion. It plays a crucial role in various fields, including gas dynamics, condensed matter physics, and particle and nuclear physics. This paper analyzes and generalizes the mean free path formula based on different physical models, aiming to guide students in identifying new problems within existing knowledge frameworks and to deepen their understanding of physical principles through inquirybased learning. The teaching approach emphasizes the application and transfer of knowledge and methods to stimulate students’ interest, foster scientific thinking, and enhance their ability to investigate physical phenomena.

Key words: the mean free path, collision frequency, collision probability, collision cross section