“用不变的量代替变化的量”是指在整个过程中某个物理量是变化的,但在某个微小过程中可近似把它看作是不变的,用不变的量代替变化的量处理问题,往往能化动为静,化变为不变,化曲为直,从而得到化难为易,化繁为简的效果.新课程注重科学思想方法的渗透,为学生掌握科学的思维方法创造了最基本的条件.“用不变的量代替变化的量”的思想方法在新课程中多处出现,现举例如下.1.知识讲解:平均速度和瞬时速度——渗透极限思想(物理必修①P18) “Replace variable quantities with constant quantities” means that a certain physical quantity is changed throughout the process, but in a small process it can be regarded as approximately constant and replaced by a constant quantity. The problem of changing quantity processing can often be turned into static, changing into unchanged, turning the song straight, so as to obtain the effect that it is difficult to make it easier to change and simplify. The new curriculum focuses on the penetration of scientific methods of thinking and masters science for students. The method of thinking creates the most basic conditions. The idea of ​​“replace the amount of change with constant quantities” appears in many places in the new curriculum. Examples are given below. 1. Knowledge: Average Speed ​​and Instantaneous Speed ​​- Permeation limit thought (physical compulsory 1P18)