论文部分内容阅读
一、受力分析是解力学题的基础 1.这种提法的根据:应用力学知识解力学题有两条基本思路:其一是应用牛顿第二定律加运动学方程,我们常把这种解法叫牛顿程序;其二是应用动能、动量定理以及守恒律。但无论用哪种思路都必须以受力分析为前提。具体说,牛顿第二定律(?)=m(?),与合外力相联系;动量定理(?)△t=mv_2(?)-mv_1(?),与合外力的冲量相联系;动能定理W外=△E_k,与合外力的功相联系。在守恒律中,合外力虽不出现,但必须进行守恒条件的分析,即确定合外力的冲量是否为零,合外力是否做功,内力有无耗散力。
First, the force analysis is the basis for solving the problem 1. This reference is based on: Applied mechanics knowledge solving problems have two basic ideas: First, the application of Newton's second law plus kinematic equations, we often put this Solution is called Newton's program; the second is the application of kinetic energy, momentum theorem and conservation law. However, no matter what kind of thinking must be analyzed by force as a precondition. Specifically, Newton's second law (?) = M (?) Is related to the resultant force; the momentum theorem? T = mv_2 (?) - mv_1 ?, is related to the impulse of the combined external force; W outside = △ E_k, and work together with external power. In the law of conservation, although the external force does not appear, it is necessary to conduct an analysis of the conservation conditions, that is, to determine whether the impulse of the external force is zero, whether the external force is used to work, and whether the internal force is dissipative.