Question

Define centripetal force? Drive expression for it ?​

Answer 1

the fore required to move the particle on its central axis is call centripital force..

$\frac{mv^{2} }{r}$

Answer 2

 Centripetal acceleration is the rate of change of tangential velocity: Consider an object moving in a circle of radius r with constant angular velocity. The tangential speed is constant, but the direction of the tangential velocity vector changes as the object rotates.

 

A body that moves in a circular motion (of radius r) at constant speed (v) is always being accelerated.  The acceleration is at right angles to the direction of motion (towards the center of the circle) and of magnitude v2 / r.