Originally Posted by
Lee_Again
My son has justed asked me this little gem; and I can't think why the correct answer is correct.
Q - When travelling at or above the speed of sound you shouldn't be able to hear an object approaching. If that's the case, can you here a Concorde engine if sat towards the front?
A - lots of errs
In theory you shouldn't be able to hear them but I guess because they are structually connected and vibrations can travel 'forwards' is, I presume, part of the correct answer but if anybody can give a more scientific reasoning I'd appreciate it. I will, shamefully, take full credit with my son. Sorry.
Thank you,
Lee
Is your question can you hear concorde coming from on the ground, or can you hear concorde's engines while inside the plane?
I think you're asking the second question. The answer to this is the same as the answer to the question "if you're sat in concorde, will you be able to hear what the person behind you is saying?". Technically, all sound is vibrations, in materials or in air. Since you are in a pressurised box, the air in the plane is at rest, and so sound can travel through the air, in this case, the sound will travel through the fuselage from the engine and then through the air in the plane.
If the air in the plane wasn't at rest, say the exit doors suddenly opened, the air would then be supersonic and no, the people at the front of the plane would not be able to hear anything from behind them (though I suspect you'd have bigger problems than not having your drinks order being heard
)