Centripetal Acceleration and Centripetal Force
A body is said to be accelerated, if the velocity of the body changes either in magnitude or in direction. Hence the motion of a stone in circularpathwithconstantspeedandcontinious changes of direction is an accelerated motion. There must be an acceleration acting along the string directed inwards, which makes the stone to move in circular path.
This acceleration is known as centripetal acceleration and the force is known as centripetal force. Since the centripetal acceleration is directed radially towards the centre of the circle, the centripetal force must act on the object radially towards the centre.
Let us consider an object of mass m, moving along a circular path of radius r, with a velocity v, its centripetal acceleration is given by
a = v2 /r
Hence, the magnitude of centripetal force is given by,
F = mass × centripetal acceleration
F = mv2 /r
In this activity, a pulling force that acts away from the centre is experienced. This is called as centrifugal force.