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? Sea level
1,000m
13,700m (within altitude used by commercial planes today)
85,000m (where meteor showers originate)

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg