[填空题]
What is the linear sps(+v9sf e.ap4j-v5 1ubce btqlt cu47 eum8,y w- )xg6k l-npqxed of a point (a) on the equator, $m/s$ (b) on the Arctic Circle (latitude 66.5$^{\circ} $ N), $m/s$ (c) at a latitude of 45.0$^{\circ} $ N, due to the Earth’s rotation? $m/s$