Question

The first supersonic flight was in 1947. It was just above the speed of sound. Which altitude would you expect Captain Yeager to have used for his flight?

Select one:
a. 85,000 m (where meteor showers originate)
b. Sea level
c. 1,000 m
d. 13,700 m (within altitude used by commercial planes today)

Answer 1

higher altitude ("thinner" air) means lower speed of sound

d. looks good

b. and c. too low , a. too high

Answer 2

I thinks it’s b