For example, a position vector in physical space may be expressed as three Cartesian coordinates with SI unit of meters.
[1][3] For example, a force on the Euclidean plane has two Cartesian components in SI unit of newtons and an accompanying two-dimensional position vector in meters, for a total of four numbers on the plane (and six in space).
For example, an event in spacetime may be represented as a position four-vector, with coherent derived unit of meters: it includes a position Euclidean vector and a timelike component, t ⋅ c0 (involving the speed of light).
A vector may also result from the evaluation, at a particular instant, of a continuous vector-valued function (e.g., the pendulum equation).
In the natural sciences, the term "vector quantity" also encompasses vector fields defined over a two- or three-dimensional region of space, such as wind velocity over Earth's surface.