From ExoDictionary
Jump to: navigation, search
This definition article has been automatically generated.
You can help ExoDictionary by expanding, updating, or correcting it.

This autostub has not yet had its initial copyediting proof and may contain significant formatting and even factual errors. You can improve Exodictionary by cleaning up the page markup and verifying that the definition is correct and then removing this tag.

This autostub has not yet had its initial categorization proof and may be categorized incorrectly. You can improve Exodictionary by removing inappropriate categories and then removing this tag.


Any quantity, such as force, velocity, or acceleration, which has both magnitude and direction at each point in space, as opposed to a scalar which has magnitude only. Such a quantity may be represented geometrically by an arrow of length proportional to its magnitude, pointing in the assigned direction. </dd>
A unit vector is a vector of unit length; in particular, the three unit vectors along the positive X-, Y-, Z-axes of rectangular Cartesian coordinates are denoted, respectively, by i, j, and k. Any vector A can be represented in terms of its components, a1, a2, and a3 along the coordinate axes X, Y, and Z, respectively; e.g., A = a1 + a2 + a3. A vector drawn from a fixed origin to a given point (X, Y, Z) is called a position vector and is usually symbolized by r; in rectangular Cartesian coordinates,

r = xi + yj + zk

Equations written in vector form are valid in any coordinate system. Mathematically, a vector is a single-row or -column array of functions obeying certain laws of transformation. See scalar product, vector product, tensor, Helmholtz theorem.
</p>[[/a>|/a> ]]


This article is based on NASA's Dictionary of Technical Terms for Aerospace Use