在力学中,轻绳、轻杆和轻弹簧不仅是三个重要的理想模型,也是三个容易混淆的形同质异的模型.为此,必须清楚它们的相同点和不同点.善于识别形同质异和形异质同的模型,建立正确的物理模型,是分析和解答物理问题的关键. In mechanics, light ropes, light rods, and light springs are not only three important ideal models, but also three confusingly homogeneous models. To do this, it is necessary to understand their similarities and differences. The same model of heterogeneity and heterogeneity, establishing the correct physical model, is the key to analyzing and solving physical problems.