CQ3

=What is a sonic boom? =

by Laura Beard and Ed Matta and Allison Rowe

A sonic boom is an impulsive noise that is caused by an object moving faster than sound.

A sonic boom is used to refer to the shocks caused by the supersonic flight of an aircraft. Sonic booms generate enormous amounts of sound energy, sounding a lot like an explosion. Thunder is a type of natural sonic boom.

When an object passes through the air, it creates a series of pressure waves in front of it and behind it. All of the waves form on top of each other because the source of the wave is moving the same speed as the waves. These waves travel at the speed of sound, and as the speed of the aircraft increases the waves are forced together, or compressed, and they eventually merge into a single shock wave, through constructive interference, at the speed of sound.

The cracking sound a bull whip makes when properly wielded is a sonic boom. The end of the whip known as the “cracker,” moves faster than the speed of sound that results in the sonic boom.

Destructive interference in waves is when two waves cancel each other out or make a smaller wave. When destructive interference occurs, no sound is heard; this corresponds to a point of no displacement on the beat pattern. Since there is a clear relationship between the amplitude and the loudness, this beat pattern would be consistent with a wave which varies in volume at a regular rate.

For more information, check out this [|video]