I would help but I’m also taking this
Probably 90 j but im not sure I haven’t done any work like this in a while
Answer: The sound will change due to changes in frequency and the wavelength of the airplane.
Explanation: Let assume that the observer is at a stationary position. The wavelength of the sound from the airplane reduces and the frequency increases as the plane is moving toward the observer. As the airplane passes by, that is, moving away from the observer, the frequency starts to reduce while the wavelength of the sound starts to increase.
The sound that the observer hears will change base on the illustration above.
Explanation:
For a circular orbit v=
with G = 6.6742 × 
Given m = 6.42 x 10^23 kg and r=9.38 x 10^6 m
=> v = 2137.3 m/s
I hope this is the correct way to solve