Circular motion

Characteristics of Circular Motion:

1.  It is an accelerated motion: As the direction of velocity changes at every instant, it is an accelerated motion. 

2. It is a periodic motion: During the motion, the particle repeats its path along the same trajectory. Thus, the motion is periodic in space. 

Uniform circular motion:

During circular motion if the speed of the particle remains constant, it is called Uniform Circular Motion (UCM). In this case, only the direction of its velocity changes at every instant in such a way that the velocity is always tangential to the path. The acceleration responsible for this is the centripetal or radial acceleration. For UCM, its magnitude is constant. It is always directed towards the centre of the circular motion, hence called centripetal. 

Non uniform circular motion:

When a fan is switched ON or OFF, the speeds of particles of the fan go on increasing or decreasing for some time, however their directions are always tangential to their circular trajectories. During this time, it is a non-uniform circular motion. As the velocity is still tangential, the centripetal or radial acceleration ar is still there. However, for non-uniform circular motion, the magnitude of ar is not constant. 

Dynamics of circular motion: