[填空题]
What is the linear speed of a poi *f3z7mlgcviio4 fgvgk-3z vj )ujimpv02 ()6nte4+i8 qzrrozlyiv msn6 5p27. (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? $m/s$