学习物理,最重要的是理解概念和规律,掌握方法,有的物理概念表面看起来比较简单,但要完整、准确理解一个概念的内涵、外延、范围以及条件是不容易的.通过下面的例子,我们一起再来体会一下.电动扶梯以恒定速率v1运行,一乘客乘扶梯上楼,第1次站在扶梯上不动,如图1所示;第2次同时? Learning physics, the most important thing is to understand concepts and laws, master methods, and some physical concepts seem relatively simple, but it is not easy to completely and accurately understand the concept of a concept, extension, scope and conditions. By the following example , we come to experience again. The escalator runs at a constant rate v1, a passenger takes the escalator upstairs, standing on the escalator for the first time, as shown in Figure 1; the second time at the same time?