机械效率是沪科版物理教材八年级学习的重点和难点,它把《简单机械》和《功》这两部分内容紧密地联系起来,综合性和应用性较强,学习过程中对“机械效率”的概念较难理解,对解答机械效率的问题缺乏基本思路。通过对教材的分析,应该把“探究滑轮组机械效率”列为学习的重点。“滑 Mechanical efficiency is the focus and difficulty of the eighth-grade physics teaching materials in the Shanghai edition. It combines the two parts of “simple machinery” and “work” closely. It is comprehensive and applicable, and it has “mechanical efficiency” in the learning process. The concept of “” is more difficult to understand and there is a lack of basic ideas for solving the problem of mechanical efficiency. Through the analysis of the teaching materials, the “inquiry pulley pulley mechanical efficiency” should be listed as the focus of learning. "slip