*** Posted by Jesus ***
Hi Chris,

You can find some brilliant photos at www.webshots.com and search with words 'Sound Barrier'. You will see some planes when they cross sound barrier.

What is that? When you are flying under sound speed the air in front of plane has enough time to adapt to the plane, but up sound speed, plane is breaking the air, air has no time to adapt. This causes a compression of air. And this leap of pression is so high that the cloud you see on pictures is produced.

Regards, Jesus

[Super sonic flight is flying above the speed of sound. Breaking the sound barrier is passing the speed of sound.
The speed of sound at sea level is 1224 km/h which equals 661 knots (NM/h) if we are talking Statute miles per hour it is more like 760. Mach two is twice the speed of sound.
The speed of sound changes with altitude.

run

Terminology:
Does Super Sonic Flight and Breaking the Sound Barrier imply the same meaning. Super Sonic does have a more polished sound to it?? At sea level what airspeed would you have to attain in order to "break the sound barrier". Preferably in miles per hour or mathmatical formula to translate knots to kilometers per hour/miles per hour. Does Mach 2 imply your traveling twice this speed? I've heard/read in order to break the sound barrier you would have to exceed approximately 725 miles per hour at sea level.

Thanks,
Chris

The mach number is thrue airspeed:speed off sound at that place.
The speed of sound is variable, it depends on temperature, airthickness, pressure. The speed of sound at sealevel, with an airpressure (qnh)1013.15, at tempeture off 0 degrees celcius is about 1200km/hour.]