What is a mass density function

The mass density of a material is defined as its mass per unit volume. Density is often understood as an indication of how heavy a substance is. Therefore, mass density is the measure of a material's compactness. The higher the density, the tighter the particles are packed inside the substance.

The mass density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume.

Density is a fundamental physical property of matter constant at a given temperature. It is commonly used as a means of categorizing and identifying different materials. In addition, a thorough understanding of the concept of density is critical for building ships and lighter-than-air crafts such as hot air balloons.

Different materials usually have different densities, so density is an important concept regarding buoyancy, purity and packaging. For example, the nature of steel depends on its content, which results in varying densities. In most cases, the denser the steel, the harder it is.