Ok, so basically the question on a test was if a a sonic boom occurs because an airplane travels as fast as sound what is it an example of. a) interference b) Doppler effect c) something else d) something else. The correct answer which my teacher marked was interference, although I think it's doppler effect and my teacher was like if you can come up with an argument supporting that it's doppler effect he would give me the point back. Considering that my grade is an 87 and i still have 6 weeks to bring it up an A i still need the extra point cus it brings my grade up to an 88. like this is how i explained it to him: because when you're standing infront of the airplane the frequency is higher because the waves "pile" up, but when you're standing under the sonic boom the frequency is lower because the waves are just going by. but my teacher needs a more "technical" argument. so can someone please help me with this.