教学有法而无定法,因此对同一节课尽可采用不同的教学方法。听了应飞老师的课从中受到启发,对本课作了如下的设想。 首先可利用起重机模型(即滑轮组装置),指导学生认识滑轮的构造,定、动滑轮的区别并画出简图。接着由“既然滑轮是一种简单机械,那么使用它是否也有省力或改变用力方向的作用”的疑问引路,让学生作如后的探究:①能否使用一个滑轮组装出 There is a law of teaching and no law, so the same class can use different teaching methods. After listening to the teacher’s lesson, she was inspired by this lesson and made the following assumptions. First of all, you can use the crane model (ie, pulley block device), to guide students to understand the pulley structure, fixed, moving pulley differences and draw a sketch. Followed by the “since the pulley is a simple mechanical, then use it whether it is also labor-saving or change the direction of the role of force” lead the way, so that students for later exploration: ① whether the use of a pulley assembly