ABSTRACT
In this chapter we consider the concepts of dimensions and units and the various systems in use for describing these quantities. In particular, the distinction between scientific and engineering systems of dimensions is explained, and the various metric and English units used in each system are discussed. I t is important that the engineer be familiar with these systems, as they are all in common use in various fields of engineering and will continue to be for the indefinite future. I t is common to encounter a variety of units in different systems during the analysis of a given problem, and the engineer must be adept at dealing with all of them.
