根据密度公式P—m／V可知：要测定物体的密度，必须先测出物体的质量和物体的体积，然后把测得的数据代人公式计算出物体的密度．测定物体密度常用的方法有下列几种：一、测形状规则物体的密度、先用天平测出它的质量m，然后用刻度尺测出它的长、宽、高或边长、直径等．算出它 According to the density formula P-m/V, it can be known that to measure the density of an object, the mass of the object and the volume of the object must be measured first, and then the density of the object is calculated using the measured data generation formula. There are several methods commonly used to determine the density of an object: 1. Measure the density of a regular object, measure its mass m with a balance, and measure its length, width, height, or length and diameter with a graduated scale. Calculate it