A supersonic jet traveling at Mach 3 (three
times the speed of sound) at an altitude of
24000 m is directly overheard at time t = 0,
as in the figure.
How far x will the plane have gone pastthe observer when it is finally heard? Assume
an average value of 329 m/s for the speed of
sound in air.
Answer in units of m
2 of 2))))
After the plane is observed directly overhead,
how long will it be before the ground observer
encounters the shock wave?
Answer in units of s
times the speed of sound) at an altitude of
24000 m is directly overheard at time t = 0,
as in the figure.
How far x will the plane have gone pastthe observer when it is finally heard? Assume
an average value of 329 m/s for the speed of
sound in air.
Answer in units of m
2 of 2))))
After the plane is observed directly overhead,
how long will it be before the ground observer
encounters the shock wave?
Answer in units of s
-
Part one... the aircraft is traveling 3 times as fast as sound. From overhead, it takes the amount of time for sound to travel 24 km. So, during that time, the aircraft travels 72 km. Before you get carried away, you don't care what the speed of sound actually is, because the speed of sound and the speed of the aircraft are identical units.
Part two... Now you need the speed of sound, to see how many seconds it takes for the sound to travel 24 km.
OK?
Part two... Now you need the speed of sound, to see how many seconds it takes for the sound to travel 24 km.
OK?