ABSTRACT
Studying, or working, in an engineering discipline, people very quickly become familiar with the standard units of measurement, the prefixes used and engineering notation. An electronic calculator is extremely helpful with engineering notation. The system of units used in engineering and science is the Systme Internationale dUnits, usually abbreviated to SI units, and which is based on the metric system. SI units may be made larger or smaller by using prefixes which denote multiplication or division by a particular amount. Density is the mass per unit volume of a substance. The symbol used for density is and its units are kg/m3. The relative density of a substance is the ratio of the density of the substance to the density of water. Relative density has no units, since it is the ratio of two similar quantities. The relative density of a liquid may be measured using a hydrometer.
