When an aircraft travels at subsonic speed, the pressure disturbances, or sounds, that it generates extend in all directions. Because this disturbance is transmitted earthwardcontinuously to every point along the path, there are no sharp disturbances or changes of pressure. At supersonic speeds, however, the pressure field is confined to a region extending mostly to the rear and extending from the craft in a restricted widening cone (called a Mach cone). As the aircraft proceeds, the trailing parabolic edge of thatcone of disturbance intercepts the Earth, producing on Earth a sound of a sharp bang or boom. When such an aircraft flies at a low altitude, the shock wave may be of sufficientintensity to cause glass breakage and other damage. The intensity of the sonic boom isdetermined not only by the distance between the craft and the ground but also by the size and shape of the aircraft, the types of maneuvers that it makes.
The atmospheric pressure, temperature, and winds. If the aircraft is especially long, double sonic booms might be detected, one emanating from the leading edge of theplane and one from the trailing edge.
IF the plane is faster than the speed of sound, the air cannot "move aside" in the usual manner, as the aircraft outruns the pressure wave that would have moved thepressure wave that would have moved theair out of the way in time. This is why fastaircraft measure their speed using the Mach number to show how fast they are in relation to sound, as this becomes the mostimportant factor once you
approach M∞=1.0M∞=1.0
end effect is that a supersonic
aircraft more forceful manner, compressing andaccelerating it to its own speed. This phenomenon is commonly called the sound barrier
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