许多同学在初学功率和机械效率时容易弄错这两个概念 ,这里我们具体分析功率和机械效率的区别。1　机械效率1 .1　人们在使用机械做的总功中 ,只有一部分有用功 ,因机械摩擦及自重等原因不得不做一些无用功 ,机械效率是有用功在总功中所占的百分比 ,机械效率高 ,说明所做的有用 Many students are prone to mistaken these two concepts when they study power and mechanical efficiency. Here we analyze the difference between power and mechanical efficiency. 1 Mechanical Efficiency 1.1 Among the total work done by people in the use of machinery, only a part of useful work has to be done due to mechanical friction and dead weight, mechanical efficiency is the percentage of useful work in the total work, mechanical efficiency. High, explains what is done