Regarding the determination of density of porous and powdered solids
Which one is heavier – a kilogram of lead or a kilogram of cotton? Or are both the same in weight?
Dear readers, the following article is not about the worst possible trick question, it is rather about the evaluation of different materials with regards to their density. In order to determine the density of a solid from its mass, it is required to determine the volume of the solid. The correct way to pose the initial question would therefore be: Which one is heavier – a cube with an edge length of one cm made of lead or a cube with the same edge length made of cotton? Or in short: Which one has the higher density, lead or cotton? Only by introducing the correct term of density, a useful labeling of materials in any field of application requiring information about masses can be carried out. This basically includes any field of applied technology – construction work, food, chemical industry, automotive and aero-space technology, pharma and medicine, cosmetics, geology or paper manufacturing.
The questions posed usually are: How many tons of grain fit into my silo? How is the ratio of a packages weight to its contents weight? How much additional mass is gained by adding an isolating layer? What is the composition of my powder mixture? Has my material changed in a process? Is this raw material or product of sufficient quality? Is my crown made of pure gold?
The answer to those questions requires a reliable way for determining density
