Supersonic and Ultrasonic

Physics

definition

Define subsonic, transonic, supersonic and hypersonic on the basis of Mach number and identify effects related to each

Mach number is defined as:
,
where:
1. M is the Mach number,
2. u is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel).
3. c is the speed of sound in the medium.

Depending upon the value of Mach number flow can be categorized as follows:
1. Subsonic:
2. Transonic:
3. Supersonic:
4. Hypersonic:

definition

Sonic Boom

When a plane travels faster than speed of sound, the plane breaks the sound barrier and produces a loud sound. This is called sonic boom.

definition

Ultrasonic and supersonic

Ultrasonic is used for ultrasound waves and is defined as waves with frequency more than 20 kHz. They cannot be heard by human beings. 
Supersonic is used for objects which travel at a speed greater than the speed of sound. These objects create sonic boom (sound associated with supersonic objects) generating enormous amounts of energy sounding like an explosion.