物体平衡问题是高中力学阶段的典型问题,其中三个力的“动态平衡”则是高考的热点问题,也是学生学习的难点.其难点一是问题多变、灵活,难点二是解决问题的规律不一定贯穿动态过程的始终,难点三是常规解题方法结果不确定性,难点四是“动态平衡”过程变化量与不变量的关系挖掘,因此,教学中教师应 The problem of object balance is a typical problem in the high school mechanics stage, of which “dynamic balance” of the three forces is a hot issue in the college entrance examination and also a difficult point for students to learn. The first is that the problems are changing and flexible, and the second is to solve the problems The law does not necessarily run through the dynamic process from time to time, the third is the result of the conventional problem-solving method uncertainty, the fourth is the “dynamic balance” process of the relationship between the amount of change and the invariants of mining, therefore, teaching teachers should