在初中物理惯性的教学中，常用这样两个演示实验来说明物体“惯性的表现”，一是把钢球放在硬纸片上，如图１，再把硬纸片沿水平方向突然弹出去，钢球没有被纸片带走，却掉进了筒里．二是用手指沿水平方向突然弹出垫在鸡蛋下的塑料片，如图２，鸡蛋并没有被塑料片带走，却平安 In the teaching of physical inertia in junior high schools, these two demonstration experiments are often used to illustrate the “inertia performance” of objects. First, the steel ball is placed on a hard paper, as shown in Figure 1, and then the hard paper piece is suddenly ejected in the horizontal direction. The steel ball was not taken away by the paper but fell into the cylinder. The second is to use a finger to pop the plastic sheet under the egg in the horizontal direction. As shown in Figure 2, the egg is not taken away by the plastic sheet, but it is safe.