Final answer:
In a supersonic wind tunnel, the air undergoes compression and heating due to the high speeds, resulting in a high-pressure and high-temperature environment which is used for experiments and testing purposes.
Step-by-step explanation:
In a supersonic wind tunnel, the air is moving at speeds greater than the speed of sound.
At this point in the test section, the air undergoes compression and heating due to the supersonic speeds, resulting in a high-pressure and high-temperature environment.
This highly compressed and heated air is then used for various experiments and testing purposes in the wind tunnel.