构建模型是解析物理问题的基础和前提·根据题设物理情景、物理过程,建立合适的物理模型,再依据模型,运用一般性原理分析、解决问题,这是一个创造性思维过程,是确定思路,寻找解题依据,快速、正确解题的重要关键·本文拟举例谈巧妙地构建模型,从而简捷、准确解题的操作途径与方 Constructing the model is the basis and prerequisite for the analysis of physical problems. According to the title of the physical scenario and the physical process, the appropriate physical model is established. Then, based on the model, the general principle is used to analyze and solve the problem. This is a creative thinking process and is a definite idea. Finding the basis for solving the problem, the key to solving the problem quickly and correctly. This article is intended to give an example of a clever way to construct a model, so that the operation approach and the solution to the problem can be solved simply and accurately.