在中学数学中 ,常会出现一些以物理知识为背景的数学题 .解决这类问题既要熟悉相关背景的物理知识 ,又要选择正确的数学手段 ,对于初中生来说有一定的难度 ,但可以激发同学们的求知欲和学习热情 .例 1　小华在探究弹簧的长度跟外力的变化关系时 ,实验记录相应的数据如下 :砝码 In middle school mathematics, there are often some math problems with physics knowledge as the background. To solve such problems, you must be familiar with the relevant physical knowledge of the background, and you must choose the right mathematics method. This is difficult for junior high school students, but you can Inspire students’ curiosity and learning enthusiasm. Example 1 When Xiaohua is investigating the relationship between the length of the spring and the change of external force, the corresponding data of the experimental record is as follows: