在物理学的问题中,往往是针对一个对象经历某一过程或处于某一状态来进行研究,而此过程或状态中,描述此研究对象的物理量有的可能是不变的,而更多的则可能是变化的。对于那些变化的量的研究,有一种方法是把全过程分为很多短暂的小过程或把研究对象的整体分解为很多个微小的局部来考察,然后通过对这些小过程或微小局部的研究而归纳出适用于全过程或者是整体的结论。这些微小过程或者微小的局部 In physics problems, research is often conducted on an object undergoing a certain process or in a certain state. In this process or state, the physical quantity describing the research object may be constant and more It may be changed. For those studies of changing amounts, there is a way to divide the whole process into many short-term small processes or to decompose the whole object of the study into many tiny parts and then study through these small processes or small localities. Summarize the conclusion that applies to the whole process or the whole. These tiny processes or tiny parts