A car mechanic “walks” two wheel/tire units across a horizontal floor as shown. He walks...

A car mechanic “walks” two wheel/tire units across a horizontal floor as shown. He walks with constant speed v and keeps the tires in the configuration shown with the same position relative to his body. If there is no slipping at any interface, determine (a) the angular velocity of the lower tire, (b) the angular velocity of the upper tire, and (c) the velocities of points A, B, C, and D. The radius of both tires is r.