Final answer:
Speeds up to Mach 0.8 are classified as subsonic. Categories like transonic, supersonic, and hypersonic are used to describe speeds in relation to the speed of sound, which affect phenomena such as sonic booms experienced when an aircraft exceeds Mach 1.
Step-by-step explanation:
Speeds up to Mach 0.8 are classified as subsonic. The categorization of speeds in relation to the speed of sound is critical in aeronautics and is defined as follows:
- Subsonic: speeds less than the speed of sound (< Mach 1)
- Transonic: speeds approximate to the speed of sound (typically around Mach 0.8 to Mach 1.2)
- Supersonic: speeds greater than the speed of sound (Mach 1 to Mach 5)
- Hypersonic: speeds much greater than the speed of sound (above Mach 5)
An example would be a jet flying at Mach 2.00, which falls into the supersonic category, as it surpasses the speed of sound (Mach 1). When a jet or any object travels through the air at such speeds, it compresses the air in front of it creating shock waves. These shock waves can combine to form a single, intense pressure wave called a sonic boom, which is heard when the pressure wave reaches the ground.
The calculation of time after which a stationary observer hears the sonic boom from a jet flying at an altitude of 8.50 km and Mach 2.00 is a physics problem involving the speed and altitude of the jet, and the speed of sound (340 m/s).