[填空题]
What is the linear spe6gtfy0fysx ;1ed of q )z3rd;wc,o)7bvo f ep;ehgnzyx 15)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? $m/s$