Supersonic speed

A F/A-18E/F Super Hornet in transonic flight

A speed is supersonic when it is greater than the speed of sound, that is, greater than 1,235.52 km/h or 343.00 m/s at sea level. Many fighter jets are supersonic. Speeds greater than 5 times the speed of sound are sometimes called hypersonic.

The white disk that forms is water vapor condensing as a result of the shock wave. This phenomenon is known as the "Prandtl-Glauert Singularity".

Breaking the sound barrier

1) Subsonic, 2) Mach 1, 3) Supersonic, 4) Shock wave

In aerodynamics, the sound barrier usually refers to the point at which an object (aircraft) moves from transonic to supersonic speed. It was an aeronautical term that came into use during World War II when aircraft began to encounter compressibility effects, an unknown aerodynamic effect. As an aircraft approaches the speed of sound, the way the air flows around its surface changes and it becomes a compressible fluid, leading to increased drag. In 1947, Chuck Yeager became the first person to cross the sound barrier in a Bell X-1. By the 1950s aircraft were routinely "breaking" the sound barrier.