所谓极端法就是对所给问题中变化着的物理现象或过程,进行夸大推向极端,在取最大值、最小值或临界值的情况下进行分析、判断;或通过放大、缩小所研究的物理现象或物理量,从而使题中的原物理现象、规律或过程充分显示出来,进而达到快速、简捷求解的目的.为了使同学们能够巧妙而灵活地利用这种解题方法,下面举例说明. The so-called extreme law is to exaggerate the physics phenomenon or process in the given problem to extremes, analyze and judge it under the condition of taking the maximum, minimum, or critical value; or by magnifying and reducing the studied physics. Phenomenon or physical quantity, so that the original physical phenomena, laws or processes in the problem are fully displayed, and then achieve the purpose of rapid and simple solution. In order to enable students to clever and flexible use of this problem-solving method, the following examples illustrate.