Motion along a straight line

The trajectory of a point that moves in a linear motion is a straight line. An origin and a direction are set arbitrarily on the line, so that the motion of this point can be described by the coordinate (motion in one dimension).

The variation of position of the point with time defines the velocity; the variation of the velocity with time is defined as acceleration.

Velocity[edit | edit source]

Definition: Average velocity is defined as the ratio between the displacement and the interval of time (in which the displacement occurs):