目前，在我国本科教学过程中，就物理学科而言，主要是给出“完美”的科学定理以及可以解析算出的习题.而恰恰某些不能解析求解的问题，能折射出同学对整个问题的理解，并可激发同学的创造力.本文针对第39届全国中学生物理竞赛复赛（备用卷）中的一道刚体力学题进行了深入分析，并结合数值计算.本文发现当球D的初始转速很小时，原参考答案的结果是合理的.此外，本文研究了球D的初始转速增大时出现的球A角速度振荡现象.通过不动点分析，估计了从线性演化到阻尼振荡转变点的临界初始转速.本文还对其中出现的一些奇异现象进行了讨论，并指出滑动摩擦力至静摩擦力的突变为稳态的出现提供了动力学对应.

Currently, in the undergraduate teaching process, particularly in the field of physics, the emphasis is mainly on presenting “perfect” scientific principles and solvable exercises. However, it is precisely those unsolvable problems that can reflect students’ understanding of the entire issue and stimulate their creativity. This paper provides an indepth analysis of a rigid body problem in the 39th National Physics Competition for high school students (alternate paper) and combines it with numerical calculations. It is found that when the initial angular speed of ball D is very small, the result given by the original reference answer is reasonable. In addition, the oscillating phenomenon of ball A’s angular velocity as the increasement of initial speed of ball D is studied. According to the analysis of fixed points, the critical initial speed at which linear evolution to damped oscillation is estimated. Some peculiar phenomena that occur during the evolution are also studied, and it is pointed out that the transition from sliding friction to static friction provides a dynamical correspondence to the occurrence of stable state.