有关浮力的计算是初中物理的一个重点,也是一难点。浮力的计算习题多是综合题,解答这类题不仅要掌握和运用阿基米德原理,还要熟练地综合运用力的的分析、二力平衡、密度公式、压力和液体压强公式等知识点。此论文针对物体浮沉的三种状态的一些问题进行从物理上教学进行深入的剖析,了解问题的本质,快速找到解决问题的方法。 Calculation of buoyancy is one of the focuses of junior high school physics, but also a difficult point. Buoyancy calculation exercises are mostly comprehensive questions, answer such questions not only to master and use Archimedes principle, but also proficiency in the comprehensive analysis of the force, the balance of two forces, the density formula, pressure and liquid pressure formula and other knowledge points . In this paper, some problems of the three states of object floating and falling are analyzed in depth from the physics teaching, and the essence of the problem is found out so that the solution to the problem can be quickly found.