Open Question: 10 Points! Physics, Earths Rotation?

The earth has a radius R = 6370000 m and rotates on its axis once every 24 hours. Point A sits on the equator while point B sits at a latitude of q = 30 degrees and point C is at the North Pole (latitude of q = 90 degrees). During a 9 hour period, how much farther does point A travel as compared to point B? Delta X = ? meters So i figured out: A(cent) = 3.35 cm/s^2 B(cent) = 2.91 cm/s^2 Thanks, this problem has been driving me nuts