学生对于有相对运动的力学系统的分析感到非常棘手,即使陷入题海战术大量做题,还是表现为:物理过程分析不清晰,物理思路混乱,物理思想茫然。下面结合这类问题提出一种分析解答思路。例题1(2004年全国高考物理Ⅰ第25题)一小圆盘静止在桌布上,位于一方桌的水平桌面的中央。桌布的一边与桌的AB边重合,如图1。已知盘与桌布间的动摩擦因数为μ_1,盘与桌面间的动摩擦因数 The students are very tricky to analyze the mechanical system with relative motion. Even if they fall into the questions of a large number of problems in the sea tactics, the students are still not clear about the physical process analysis, the confusion of the physical thinking, and the dilemma of the physical thinking. The following combination of such problems put forward an analysis of ideas. Example 1 (National Physics Entrance Examination 2004 Question 25) A small disc rests on a tablecloth, centered on a horizontal table top of a table. One side of the tablecloth coincides with the AB side of the table, as shown in Figure 1. It is known that the dynamic friction coefficient between the plate and the tablecloth is μ_1, the dynamic friction coefficient between the plate and the tabletop