Note: The activities in this module make reference to the computer algebra system (CAS) Maple, and links are provided to download Maple files. Any other CAS can be used instead (e.g., Mathematica, Mathcad, etc.) as long as the user is familiar with that CAS system. Maple is not required for the use of the ideas in this module, but it is required for opening and executing the downloadable files.

Larry Gladney is Associate Professor of Physics and Dennis DeTurck is Professor of Mathematics, both at the University of Pennsylvania.

Equations are used to describe the motion of objects. Usually the independent variable in these equations is *t*, for time. Depending on whether the motion is taking place along a line (one dimension), in a plane (two dimensions), or in space (three dimensions), we use one, two or three functions to specify the position of the object at any time. This module concerns the process of changing the point (and direction) of reference from which the motion is viewed -- this is important for solving physics problems, designing automatic pilots and other robotic devices, and video games.

Journal of Online Mathematics and its Applications