Research on the reversal of hard-ball system in two-dimensional bowl

TL;DR

This paper investigates the dynamics of multiple hard balls in a rotating two-dimensional bowl, revealing how increasing the number of balls causes a reversal in their movement trend, with implications for complex physical systems.

Contribution

It introduces a physical model of hard-ball systems in a rotating bowl and analyzes the movement reversal phenomenon as the number of balls increases.

Findings

Small number of balls move with the bowl's rotation

Increasing balls causes movement trend reversal

Model can be used for physics education

Abstract

Putting several hard balls into a two-dimensional bowl can form a very basic two-dimensional model of hard-ball system. When the two-dimensional bowl has a parallel-rotation at a uniform speed around a center, when the number of balls is small, the direction of motion of the small balls in the two-dimensional bowl is consistent with that of the two-dimensional bowl; However, when we increase the number of balls one by one, the two will seem to show the opposite movement trend. We analyze this problem comprehensively through physical modeling and inspire readers to think about the significance of the model for analyzing complex physical problems. Finally, because this article involves many aspects of knowledge, college physics teachers can choose the whole problem or part of the problem to introduce it into the classroom.