把共点力平衡说成高中物理最基础最重要的知识一点也不为过,每年全国各地高考都有其新面孔出现.要想迅速准确地解答此类试题,必须把握好受力分析、平衡条件等知识.但有时仅仅熟悉这些知识还不够,还要用到简谐运动、动能定理等其他知识来解决问题.2008四川理综第21题既是一道难? It is not an exaggeration to say that common-point balance is the most basic knowledge of high school physics. Each year, the national college entrance examination has its new face. To quickly and accurately answer such questions, we must grasp the force analysis and balance. Conditions and other knowledge. But sometimes it is not enough just to be familiar with this knowledge, but also to use simple harmonic motion, kinetic energy theoretics and other knowledge to solve the problem. 2008 Sichuan issue 21 is not only a difficult problem?