初中物理“重力”一节，只是抽象地给出了重力的概念，没有用形象的实验来显示“产生重力”原因，既不利于学生的形象思维，也不利于学生对“重力”概念的正确认识，对此笔者设计了一个演示实验装置，介绍如下。 　　器材：铁制地球仪一个，磁铁若干块，做一脚下粘一铁钉的纸人 The “gravity” section of junior high school physics only gives the concept of gravity abstractly. It does not use image experiments to show the cause of “gravity generation”. It is not conducive to students’ image thinking, nor is it conducive to students’ correctness of the concept of “gravity.” Recognize, this author designed a demonstration experiment device, introduced as follows. Equipment: One globe made of iron, a few magnets, and a paper man with a nail under one foot