11
1.6 Types of Motion: Uniform (constant) and Non Uniform Motion
1.6.1 Uniform motion
Uniform motion is defined as:
Motion on a straight line, and
Occur when successive displacement/distances are equal at equal time intervals
If you drive a car at a constant velocity of 80 km/h, you will cover 80km during the first hour, another
80km during the second hour, another 80km during the third hour, and so on. The 80km covered during
each hour is not the position but the change of position or displacement. Also, the time of 1 hour is the
time interval between successive equidistance displacements. On ( x, t ) diagram, the uniform motion is
shown as straight line with a slope giving the velocity. Figure (1.5(a)) illustrates a pictorial and graphical
representation of uniform motion in ( x, t ) plane.
1.6.2 Non Uniform Motion
Non Uniform motion is defined as:
Motion on a curve, and
Occur when successive displacements/distances are not equal at equal time intervals
A pictorial and graphical representation of non uniform motion is shown in Figure (1.5 (b))
(a)
(b)
Figure 1.5: pictorial and graphical representation of a uniform (a) and (b) non uniform motions . The term frame referes to an event.
Credit: Physics for scientists and engineers strategic approach” by Randall D. Knight, Pearson-Addison Wesley 2004.