问题:一根均匀,横截面积为圆形的由细变粗的长棒,如果通过它的重心,且沿轴线的垂直方向将它截成两段,问哪一段重?(见图1)这个问题,曾在1987年《物理教学》第5期上由上海师大陈静秋同志用积分法给出一种解法,很受启迪.陈静秋同志着重阐述了长棒表现为圆锥台的情况.本文将用初等几何法讨论 Problem: A uniform, long, thin, thick bar with a circular cross-sectional area, if passing through its center of gravity and cutting it into two sections along the vertical axis, ask which section is heavy (see Figure 1). This question, which was once given by Shanghai Normal University’s Chen Qiuqiu in the fifth issue of Physics Teaching in 1987, was given a solution by the integral method. It was very enlightened. Comrade Chen Jingqiu focused on the performance of the long rod as a cone. Discuss with elementary geometry