[填空题]
What is the linear speedt8q n09 sqlo4vc9))k zkd8 tdn of 9qihc9j3v5mb fz 4b 6mxvj+c4q6 iv(5 zoajj0a 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? $m/s$