【教材分析】《机械效率》是苏科版物理教材第十一章第五节的内容,是继功、功率之后另一个非常重要的物理概念.教材在之前已经安排了有关于各种简单机械和功的内容学习,《机械效率》是在此基础上的进一步延伸,也可以说是对这些内容的综合分析和实际应用,体现了物理知识最终要服务于生产和生活的理念.【学情分析】学生在本节前学习了滑轮、杠杆、斜面等一些简单机械,知道这些机械使用过程中的特点,为本节内容的学习做好了铺垫.学生还学习了功的概念,会分 【Teaching material analysis】 “Mechanical efficiency” is Su Ke version of the textbook Chapter XI of the content of the fifth section, is the successor, power after another very important physical concepts. Textbook has been arranged before a variety of simple machinery And learning the content, “mechanical efficiency” is based on this further extension, it can be said that the comprehensive analysis of these contents and the practical application, reflects the physical knowledge ultimately to serve the concept of production and life. Analysis Students learned a few simple machines such as pulleys, levers, bevels and so on before this section to learn the characteristics of these machines in use and to pave the way for the learning of this section. Students also learned the concept of work,