In order to understand why some combinations of alkyl halides and nucleophiles give a substitution reaction, whereas other combinations give elimination, and still others give no observable reaction, we must investigate systematically the way in which changes in reaction variables perturb the course of the reaction.
It's true - the ISS moves at about 17,000 mph (~28,000 kph). Now for your other questions: 1. When it's not using its onboard engines to adjust its orbit, the station is in free-fall*. This means that gravitational interaction with the earth maintains the station's orbit, and thus its speed.
Astronauts are by far the fastest traveling humans with the earth as a stationary reference point. One might think the Apollo missions to the moon are the fastest traveling humans, but the speed of that spacecraft was only about 6,300 miles per hour. In fact, an orbiting space shuttle is much faster at 17,600 miles per hour. This is the fastest any man has reached. Although it seems very fast to us, this speed is 0.026% of the speed of light. For unassisted speed using Usain Bolt's time in the 100 meter, his top speed is 23.3 miles per hour (10.4 m/s).