【背景】密度的测量实验,当条件不同时,实验方法各异,可成为发展学生智力、考察学生能力的一个很好的载体,因而在初中物理教学中占有较重的分量。但由于密度的测量设计题综合性强,测量工具涉及天平、量筒、弹簧秤、刻度尺等,应用的知识涉及质量、体积的测量、阿基米德原理、物体浮沉条件、压强、二力平衡等,数据处理涉及到代数运算与列方程 [background] Density measurement experiments, when the conditions are different, the experimental methods are different, can become a good carrier for the development of student intelligence, study of student ability, and therefore occupies a heavier weight in junior middle school physics teaching. However, due to the comprehensiveness of the density measurement design questions, the measurement tools involve balances, graduated cylinders, spring scales, scales, etc. The applied knowledge relates to the measurement of mass and volume, Archimedes’ principle, object floatation conditions, pressure, two-force balance, etc. , data processing involves algebraic operations and column equations