A flat dance floor of dimensions 20.0 m by 20.0 m has a mass of 1 000 kg. Three dance couples, each of mass 125 kg, start in the top left, top right, and bottom left corners.
(a) Where is the initial center of gravity?
(b) The couple in the bottom left corner moves 10.0 m to the right. Where is the new center of gravity?
(c) What was the average velocity of the center of gravity if it took that couple 8.00 s to change positions?