o
Point Po have opposite velocities , and if condition of no-slipping is there then it must have zero velocity , so Vcom = ω R
o At point P1 both the velocities add up . o
o
At any other point , add both the velocities vectorially to get the resultant , which are shown for some of the cases in red color in figure .
The line passing through PO and parallel to w is called the instantaneous axis of rotation .
o The point PO is instantaneously at rest . o
Kinetic Energy of Rolling Motion o
KErolling = KEtranslation + KErotation
Example - A hoop of radius 2 m weighs 100 kg . It rolls along a horizontal floor so that its centre of mass has a speed of 20 cm / s . How much work has to be done to stop it ?