例1一小球用一根细绳系在光滑竖直墙面上，处于静止状态（如图1）．请画出小球的受力示意图．错解1如图2．错解2如图3．辨析错解产生的原因是没有掌握正确的受力分析的方法．对物体进行受力分析时应注意：第一，应确定研究对象，即一定要明确是哪一个物体的受力情况；第二，分 Example 1 A ball is tied to a smooth vertical wall with a string and is at rest (Figure 1). Please draw a sketch of the force of the ball. The wrong solution 1 is shown in Figure 2. The wrong solution 2 is shown in Figure 3. The reason for distinguishing the wrong solutions is that there is no way to grasp the correct force analysis. When performing force analysis on an object, attention should be paid to: First, the research object should be determined, that is, it must be clear which of the object’s stress conditions; second, points