When the sound barrier is broken, it refers to the phenomenon known as supersonic flight. The sound barrier is the popular term for the speed of sound, which is approximately 343 meters per second (or about 1,235 kilometers per hour) in dry air at 20 degrees Celsius (68 degrees Fahrenheit).
When an object, such as an aircraft, travels at speeds approaching and exceeding the speed of sound, several effects occur. At subsonic speeds (below the speed of sound), the air particles can move away from the object without much disturbance. However, as the object approaches the speed of sound, the air particles start to compress and generate pressure waves in front of the object.
As the object reaches and surpasses the speed of sound, these pressure waves become highly concentrated and form a shock wave, also known as a sonic boom. The sonic boom is the sudden, loud noise often associated with breaking the sound barrier. It occurs when the compressed air particles are suddenly released as the object passes through the speed of sound, creating a rapid pressure change.
The sonic boom is characterized by a sharp increase in pressure followed by a decrease, resulting in a distinctive "boom" sound. It is important to note that the sonic boom occurs not only when breaking the sound barrier but also when the object maintains supersonic speeds.
The effects of breaking the sound barrier can vary depending on the specific aircraft and conditions, but some common characteristics include increased drag, potential structural stress on the aircraft, and the generation of shock waves. Specialized designs and techniques are employed to minimize these effects and enable safe and efficient supersonic flight.