Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....

Unit Vector Notation

When we want to specify a vector by its components, it can be cumbersome to have to write the algebra symbol for each component:

A more compact notation is to write

where the vectors

, called the unit vectors, are defined as the vectors that have magnitude equal to 1 and directions lying along the x, y, and z axes. In speech, they are referred to as "x-hat" and so on.

A slightly different, and harder to remember, version of this notation is unfortunately more prevalent. In this version, the unit vectors are called

Last Update: 2009-06-21