通常把两个或两个以上叠加在一起的物体称为叠加体,它们相对静止时,彼此间的摩擦力为静摩擦力,当静摩擦力达到最大静摩擦力时,叠加体也就达到了相对滑动的临界状态.但由于叠加体间有多个静摩擦力,它们相互关联,所以具体到哪个接触面先达到临界状态或接触面间是否达到临界状态就非常隐蔽,很难识别.针对这两类识别疑点分类介绍对应的破解方法.一、哪个接触面先达到临界状态1.平衡时图1例1如图1所示,A、B、C三个物块叠 Usually two or more superimposed objects called superposed body, they are relatively static, the friction between each other for the static friction, when the static friction reaches the maximum static friction force, the stack also reached a relative sliding However, due to the multiple static friction between superposition bodies, they are related to each other, so it is very difficult to identify which contact surface first reaches the critical state or whether the contact surface reaches the critical state. Classification introduced the corresponding method of cracking. First, which contact surface to reach the critical state 1. Balance Figure 1 Example 1 As shown in Figure 1, A, B, C three blocks stack