A vector quantity V is represented by a line segment,
having direction of the vector and having an arrowhead to indicate the sense.
The length of the directed line segment represent to some convenient scale the
magnitude of vector |V|and is printed with light-face italic type V. For example, we may choose a scale
such that an arrow one inch long represents a force of twenty pounds.
In scalar equations, and frequently on diagrams where only the
magnitude of a vector is labeled , the symbol will appear light-face
italic type. Boldface type is used for vector quantities whenever the
directional aspect of is a part of its mathematical representation. When
writing vector equations, always be certain to preserve the mathematical
distinction between vectors and scalars. In handwritten work, use a
distinguishing mark for each vector quantity such as an underline, V, or an arrow over the symbol
to take the place of boldface type in print.
