众所周知,数学是解决物理问题的有力工具,反之,在解决某些数学问题时,构造物理模型,应用物理思想,也会使问题的解决变得更加简捷明了.本文就中学生所熟知的光行最速原理、杠杆原理、势能最小原理通过三个实例加以说明,供参考. As we all know, mathematics is a powerful tool for solving physical problems. Conversely, when solving certain mathematical problems, the construction of physical models and the application of physical ideas will also make the resolution of problems more concise and clear. This article focuses on the speed of light that middle school students are familiar with. The principle, principle of leverage, and principle of potential energy are illustrated by three examples for reference.