浮力及阿基米德原理在初中力学中 ,既是重点 ,又是难点 .如果只知其然 ,不知其所以然 ,就易出错 .为使学生理解透彻 ,本文对浮力难点的突破作些探索 .1　从实验上突破首先依照教材通过实验总结出阿基米德原理 :浸在液体里的物体受到竖直向上的浮力 ,浮力的大小等于被物体排开的 The principles of buoyancy and Archimedes in junior middle school mechanics are both important and difficult. If you only know what you know, you are not sure why it is. You are prone to making mistakes. To make students understand thoroughly, this article explores the difficulties of buoyancy.1 From the experimental breakthrough, firstly according to the teaching materials, the principle of Archimedes was concluded through experiments: objects immersed in liquid are subject to vertical upward buoyancy, and the size of buoyancy is equal to that of objects