A disc is rolling (without slipping) on a horizontal surface. C is its centre and Q and P are two points equidistant from C. Let vp,vQ. and vC be the magnitudes of velocities of points, P, Q and C respectively, then

If O be the point of contact of the disc with the surface , then at any instant of time the disc is rotating about point o and O is called the instantaneous centre of rotation . Velocity of any point on the disc at a radial distance r from O is given by V = ωr.OQFrom fig. OQ > AC > OPWe know that V=rω∴ vQ>vC>vP