物理系统(或质点)由于某些原因而发生突变时所处的状态,叫临界状态.发生突变的过程是从量变到质变的过程.在临界状态前后,系统(或质点)遵守着不同的规律,按不同的规律运动和变化,高中物理教材中明确提出的“临界温度”、“临界角”、“临界体积”都是例子. 从中学生学习的实际情形来看,明确指出的临界值是容易理解和掌握的,而这几年高考题中常出现的临界值问题,常常是不明确提出临界值而又必须通过运用所学知识去挖掘临界值,才能求解的问题,这是为了拉开差距,有利于选拔人才的问题.根据笔者多年教 The state in which a physical system (or particle) undergoes mutation for some reason is called a critical state. The process of a sudden change is a process from quantitative to qualitative change. Before and after the critical state, the system (or particle) observes different laws. According to different laws and movements, the “critical temperature”, “critical angle”, and “critical volume” clearly specified in the high school physics textbooks are examples. From the actual situation of middle school students, it is easy to specify the critical value. Understanding and mastering, and often appearing in the college entrance examination questions in recent years, the critical value problem is often not explicitly put forward the critical value, but must be used to find the critical value through the use of knowledge to solve the problem, this is to open the gap, The problem of facilitating selection of talents. According to the author for many years