The speed of the train is 0.025 km/s, the speed of a supersonic plane is 0.5 km/s, and the speed of a rocket is 4.5 km/s. Please propose two mathematical problems solved by division and answer them.
火车的速度是0.025千米/秒，超音速飞机的速度是0.5千米/秒，火箭的速度是4.5千米/秒，请提出两个用除法解决的数学问题并解答．
<gadget id="calculator">4.5 / 0.5</gadget>
<output>9</output>

<result>9</result>