Question

if the velocity of the point of contact in ideal and pure rolling motion at any instant is 0 then how is the body moving and the point of contact doesn't remain stationary?

Answer 1

Because it's a different point of contact at each different instant.
For a circular wheel rolling on a straight base, each point of contact on the wheel will move in a cycloid. Only at the cusp on the cycloid is the instantaneous velocity zero.

Answer 2

yeah but if at a particular instant if the velocity at the point of contact is 0 and neither velocity of centre of mass is changing nor the 'wR' angular velocity changes..then how is another point on the circumference coming down to replace the previous point of contact?

Answer 3

Because the process is continuous.

Answer 4

a guy rolls a cylindrical drum by pushing the board across the top.
so in this case what length of board rolls over the top of drum?
how far does the guy walk??
(no sliding of the board with the drum and no sliding with ground)
particularly i am not getting the second question.