机械能守恒定律是高中物理学中的一个重要知识点．我们以教材为基础，从实验室中取材，设计制作了“机械能守恒”演示仪，现介绍如下．１　演示仪的材料与制作 演示仪结构如图１所示． （１）金属片：观察、研究的对象．要求用质量较大且带有窄缝的矩形金属片．（参考值：金属 The conservation of mechanical energy is an important knowledge point in high school physics. Based on the teaching materials, we took materials from the laboratory and designed and produced the “mechanical energy conservation” demonstrator, which is introduced as follows. 1 Demonstration instrument materials and production Demonstration instrument structure is shown as in Fig. 1. (1) Metal pieces: Observed and studied objects. Requires a larger rectangular sheet metal with narrow slits. (Reference value: Metal