What is the frequency, amplitude, wavelength, etc. of a sound wave at the sound barrier?
The sound barrier is something of a myth that dates to the early days of transonic flight. As early airplanes approached the speed of sound, they suffered various flight instabilities—a significant rise in air drag and a tendency for supersonic shock waves to interfere with the operations of control surfaces. Exceeding the speed of sound appeared problematic at the time and the expression “the sound barrier” came into common use. However, there is no real sound barrier. Once Yeager had exceed the speed of sound in an experimental plane, it became clear that the speed of sound was not a firm barrier. However, there is one peculiar thing that does happen once a plane has exceeded the speed of sound. You can no longer hear the plane coming because it is outrunning its own sound waves. Instead of having its sound spread out in front of it, the plane has its sound swept back in a cone behind it. The edges of this cone are a shock wave and you experience a sudden pressure rise as this cone p
