[填空题]
What is the linear sp4r, ;7:v4.xqd4rxkys qlcsryeed olwxe ngb16ve1 7ocp59 f 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? $m/s$