“浮力”一直是初中物理教学的重点与难点,它所涉及的知识内容,思维形式也一直是对学生进行思维训练,培养能力的好素材.由于该章内容涉及的相关知识点多,问题的种类繁杂、变化多种多样,许多学生常常会对浮力习题感到理不清思路,无从下手.尤其当浮力知识与压强知识综合,出现三个不同的底面积时,更是搞不清该用哪个面积,因此正确区分浮力问题中的三个底面积尤为重要,现举例说明. “Buoyancy” has always been the focus and difficulty of junior high school physics teaching. The knowledge content and thinking forms involved in it have always been good materials for students’ thinking training and cultivation ability. Because the chapter contains many related knowledge points, The types of problems are complex and varied. Many students are often confused about buoyancy exercises and have no way of starting. Especially when buoyancy knowledge and pressure knowledge are combined and three different bottom areas appear, it is even more difficult to understand Which area is used, so it is important to correctly distinguish the three bottom areas in the buoyancy problem.