The Sonic Boom
When an object travels faster than the speed of sound in a fluid, it generates a shock wave. The shock wave forms a cone from the front of the object and spreads out to form a trailing cone, as shown below for a supersonic plane.
The shock wave travels at the speed of sound – about
or
at sea level at a temperature of 20 degrees celsius. The speed of sound is labelled Mach 1. The half angle
between the line of flight of the object and the shock wave is given by
- The fast the object, the more point the cone.
- In fact two booms are experienced by observers. One as they enter the cone and one as they leave it.
- A may generate a small sonic boom. A bullwhip tapers down from the handle section to the end, which is much lighter than the handle. When the whip is swung, energy is transferred down the length of the tapering whip. In accordance with the formula (if the work for whipping remains constant) for kinetic energy
the velocity of the whip increases with the decrease in mass,so if the whip is swung fast enough, a sonic boom may be generated.
