Linear motion (also called
rectilinear motion) is a
motion along a
straight line, and can therefore be described mathematically using only one spatial
dimension. The linear motion can be of two types: uniform linear motion with constant velocity or zero acceleration; non uniform linear motion with variable velocity or non-zero acceleration. The motion of a particle (a point-like object) along a line can be described by its position
![](http://info.babylon.com/onlinebox.cgi?rt=GetFile&uri=!!ARV6FUJ2JP&type=0&index=118)
, which varies with
![](http://info.babylon.com/onlinebox.cgi?rt=GetFile&uri=!!ARV6FUJ2JP&type=0&index=3854)
(time). An example of linear motion is an athlete running 100m along a straight track.