Density topic

In physics and materials science the density (ρ) of a body is a measure of how tightly the matter within it is packed together, and is given by the ratio of its mass (m) to its volume (V). Its SI units are kilogram per cubic metre (kg/m³). It is also sometimes given in the cgs units of gram per cubic centimetre (g/cm³). Density is defined as: Different materials usually have different densities, so density is an important concept regarding buoyancy, metal purity and packaging. In some cases... full article at wikipedia