在多年的教学中,笔者采用等效法处理一类问题,比较简洁,学生易于接受,可有效地发散学生的思维.例1:杯中盛有水,夹有铁块的冰漂浮在水面上,如图1所示.冰熔化后:A.冰面将上升 B.水面将下降C.水面高度不变 D.无法确定我们可以认为铁块连接在冰的下部,如图2所示,由于铁的密度比水的密度 In years of teaching, the author used the equivalent method to deal with a class of problems, which is relatively simple and easy for students to accept. It can effectively diverge students’ thinking. Example 1: The cup contains water, and iron with iron blocks floats on the water. As shown in Fig. 1. After the ice melts: A. The ice surface will rise B. The water surface will fall C. The water surface height does not change D. There is no certainty that we can think of iron pieces connected to the lower part of the ice, as shown in Fig. 2, due to the iron Density than water density