Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

but does the pilot hear the sonic boom?



At 3:46 PM -0600 11/24/03, Jorge Salazar wrote:


*********************************************************
Wednesday, November 26, 2003
SOUND SPEED
Sound waves move at about 340 meters per second -- about two-tenths of a
mile per second. A listener wonders if you can hear anything when you
travel faster than sound. The answer -- after this on Earth and Sky.
_________________________________________________________

DB: This is Earth and Sky. When we visited the National Air and Space
Museum in Washington D.C., we got this question.

Caitlin Rush: My name's Caitlin Rush, and I'm from State College,
Pennsylvania , and I ask, "When you're traveling at the speed of sound or
faster can you hear anything?"

JB: Caitlin, the answer is yes. Imagine you're seated in a parked car.
You switch on the radio. The car's speakers begin to vibrate. The speaker
cone presses against air molecules near the speaker, which push against
neighboring air molecules. Much like firefighters passing a bucket, this
wave of pressure eventually reaches your ears. Your brain interprets this
wave of pressure as sound.

DB: Now imagine you attach a pointy nose to your car and add enough
horsepower to break the sound barrier. As you cruise at more than 340
meters per second -- that's more than two-tenths of a mile per second -- or
faster than the speed of sound -- you reach over and switch on the radio.
Your car -- and you -- and all the air molecules around you -- are
traveling that fast. So the sound wave pushes away from the vibrating
speakers in exactly the same way it did in the parked car, and you can hear
the sound.

JB: And that's good news for pilots and passengers of supersonic aircraft!
Thanks for your question, Caitlin. And with thanks to the National Science
Foundation, we're Block and Byrd for Earth and Sky.

http://www.earthsky.com/2003/es031126.html


*********************************************************