一、“称重法”测固体和液体的密度:如用弹簧测力计、水和烧杯测石子和牛奶的密度。分析:石子的密度ρ=m/v,由于石子在水中下沉而浸没在水中,所以排开水的体积就是石子的体积,而排开水的体积可以通过水中石子所受浮力来算出,石子受到的水的浮力可以利用弹簧测力计通过称重法来测量,同时弹簧测力计还测量了石子的重力进而得到它的质量,这样石子的密度就可以求出。同样,牛奶的密度可以利用阿 First, the “Weighing Law” to measure the density of solids and liquids: such as using a spring dynamometer, water and beakers to measure the density of stones and milk. Analysis: the density of stones ρ = m / v, because the stones submerged in the water and immersed in water, so the volume of water is the volume of stone drainage, and the volume of water can be discharged through the water buoyancy to calculate the buoyancy, The buoyancy of the water can be measured by the spring dynamometer through the weighing method. At the same time, the spring dynamometer also measures the gravitational force of the gravel to obtain its mass, so that the density of the stone can be obtained. Similarly, the density of milk can use Ah