功的原理是许多机械师和科学家经过长期的实践和研究,到18世纪才为人们所认识,即“使用任何机械都不省功”。这个原理在历史上曾被誉为“机械的黄金定律”。这说明它对机械的使用和研制,具有重要的指导意义。功的原理的叙述本来是简要和明白的,然而笔者曾多次发现一些教师在教学实践中对功的原理的认识并不一致,例如有的教师把功的原理浓缩成W_机=W_人。还有一些老师认为功的原理是有前提条件的,也就是在没有(或者不考虑)摩擦和其它阻力的情况下才能使用。而对下面一道题的不同选择更说明认识的不一致。题目:对功的原理的理 The principle of work is that many mechanics and scientists have long been practiced and researched until the 18th century, and they were known by people. That is, “the use of any machinery does not save energy.” This principle has historically been hailed as the “golden law of machinery.” This shows that it has important guiding significance for the use and development of machinery. The narrative of the principle of work was originally concise and clear. However, the author has repeatedly found that some teachers have inconsistent knowledge of the principles of work in teaching practice. For example, some teachers concentrate the principle of work into W_machine=W_people. . Some teachers believe that the principle of Gong is precondition, that is, it can be used without (or considering) friction and other resistance. The different choices for the following question further illustrate the inconsistency of understanding. Topic: Theory of the principle of work