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Re: but does the pilot hear the sonic boom?



To hear his own shock wave (if a pilot) or swim over his own wake (if a duck) the individual just has to turn in a circle, no?
skip

-----Original Message-----
From: Frohne, Vickie [mailto:VFrohne@BEN.EDU]
Sent: Monday, December 01, 2003 15:32
To: PHYS-L@lists.nau.edu
Subject: Re: but does the pilot hear the sonic boom?


The shock wave travels at *precisely* the speed of sound. The sonic boom
occurs when the shock wave intercepts a listener, presumably a stationary
listener on the ground. The sound is heard as a "boom" because the shock
wave is moving past the listener. It's here, then it's gone.

Consider the following: If the pilot could hear the sonic boom, what would
it sound like? Not a boom, because the plane is making the "boom"
continuously and the pilot is traveling with it. It would have to be a
steady roar, transmitted to the pilot through the frame of the airplane
rather than through the air surrounding the plane, because the plane is
outrunning the sound waves made in the air surrounding the plane.

It might be easier to imagine the situation by thinking about the wake
created behind a duck swimming on a pond. A duck's wake has *exactly* the
same origin as a sonic boom. It is created because the duck swims faster
than the speed of waves in the water. A stick floating near the edge of the
pond will bob up and down violently as the wake passes...the "water boom."
Does the duck ever intercept its own wake and experience a "water boom"? Not
likely.

Vickie Frohne
-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@lists.nau.edu]On Behalf
Of Karl Trappe
Sent: Monday, December 01, 2003 1:49 PM
To: PHYS-L@lists.nau.edu
Subject: Re: but does the pilot hear the sonic boom?


Was it Aristotle who said "Answer a question but with a question"?

I think the given answer is to a totally different question. It is
not can the pilot hear what is in the cockpit, but can the pilot hear
his own sonic boom?

Perhaps the shock wave travels faster than the speed of sound in air.
I think that is the physics question.

Karl