[填空题]
What is the linear spbf9l.7a3,bc kl(ueu 4.x qwc reedfl1 :jhv fg 7nd.i/8m1woj-.fn2fbet 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? $m/s$