等效的概念是初中物理中的重要概念,等效法作为一种解题思路和方法,在力的合成、合力与分力、串联和并联电路、液体的压强等题目的解答中应用较广,有时用等效法可以大大简化繁琐的计算,不仅可以提高答题质量,还可以提高分析物理问题的能力,现笔者举解两例. The concept of equivalence is an important concept in junior middle school physics. Equivalent method is used as a problem-solving idea and method. It is widely used in the solution of problems such as force synthesis, resultant force and force, series and parallel circuits, and liquid pressure. Sometimes using the equivalent method can greatly simplify the cumbersome calculations, not only can improve the quality of the answer, but also can improve the ability to analyze physical problems, the author presents two examples.