力学不仅在中学物理中教学时数最多,而且掌握了力学问题的研究方法,其他问题都可迎刃而解。然而,无论教师怎样努力,绝大多数学生还是不能找准解决力学问题的切入点。学生一看到力学问题就自然想到了牛顿定律。应该说,学生的这种思维并没有错,但实践却让学生在很多情况下难堪:要么繁,要么根本解决不了。为了绝大多数解决学生这一实际问题,笔者除了在进行牛顿定律、动量、机械能的教学时向学生讲清楚定理、定律本身和三者的相互联系以外,还重点强调因为动量是力的时间效应、能量是力的空间效 Mechanics not only has the most teaching hours in middle school physics, but also masters the research methods of mechanics problems, and other problems can be solved easily. However, no matter how hard teachers try, the vast majority of students still can not pinpoint the starting point for solving mechanics problems. As soon as the students saw the mechanical problems, they naturally came up with Newton’s law. It should be said that this thinking of students is not wrong, but practice makes students embarrassed in many cases: either complicated or simply can not be solved. In order to solve the practical problem of the vast majority of students, in addition to clarifying the theorems, the law itself and the interrelationship of the three, New York’s law, momentum, mechanical energy, the author also emphasizes the time effect because momentum is a force Energy is the space effect of force