物理中经常出现多过程问题,学生一般习惯于对每个过程逐个分析,看各过程存在什么规律,分别列方程,最后求解.这样导致所列方程较多,解题费时.有时由于各过程中不确定因素太多,应用高中数学知识求解特别麻烦,甚至无法求解.这时若纵观整个过程,选定明确的初状态和末状态,可使解题步骤大为缩 There are often many process problems in physics. Students are usually accustomed to analyzing each process one by one to see what rules exist in each process, and then formulating the equations and finally solving them. This results in more equations listed and time-consuming solutions. Too many uncertainties, the application of high school mathematics knowledge to solve particularly troublesome, even unable to solve .At this time if we look at the entire process, the choice of a clear initial and final state,