on a rolling wheel, the point touching the ground on that wheel is not moving. i.e. it has an instantaneous speed of 0. it can even be seen in a photograph. derpy derp its not photo shop so stfu.. rolling motion is made of two things: rotation (spinning) and translation (moving from a to b). If there is a tiny pebble getting run over by a tire, for a split second as the tire is directly on top of it, the contact point on the tire is not moving. the tire is not rotating because there is no distance between the pebble and the contact point (the pebble is the contact point). Its not moving from a to b because it is not rotating, and it is also not sliding or skidding.
