4. The fastest airplane to date was the X-15, with a top speed of mach 6.7, or 7200 km/hour. *If* the X-15 had had the range to fly from coast to coast (a distance of 4000 km),
a.) how long, in s, would that take according to a clock on Earth?
b.) how much less time, in ms, would elapse on a clock contained in the X-15? (Hint: you will need the Binomial expansion, in the appendix to Tipler and Llewellyn, page AP-18)
Answer: The less time, in ms,... View the full answer