Non–uniform circular motion of Earth around the sun:
When a particle moves or circular path with varying speed then motion of particle is called non–uniform circular motion.
In non–uniform circular motion particle have three type of acceleration.
(a) Radial acceleration : When a particle moves on circular path then velocity of particle continuously changes because direction of velocity continuously changes. Due to change in direction of velocity, acceleration generates inside the particle which have direction always towards the center of circular path. This acceleration of particle is called Radial or centripetal acceleration.
(b) Tangential acceleration : In non–uniform circular motion speed of particle continuously changes. Due to change in magnitude of velocity, acceleration generates in particle which has direction along the tangent drawn and this acceleration is called tangential acceleration.
(c) angular acceleration : In non–uniform circular motion angular velocity of particles also changes. The rate of change of angular velocity is called angular acceleration.
In non–uniform circular motion, the size of the velocity vector (speed) changes, denoting change in the magnitude of velocity. The change in speed has implications for radial (centripetal) acceleration. There are two possibilities :
- the radius of the circle is constant
- the radial (centripetal) force is constant. In either case, the angular velocity in non–uniform circular motion is not constant, as ω = v/r, and “v” is varying.