Final answer:
Vortex generators help delay shockwave formation by energizing the boundary layer, which helps delay flow separation and the onset of mach buffet. Sweeping the wings back also delays drag caused by shockwave formation, and when transitioning from warm to cold air, an aircraft must decrease its speed to maintain a constant Mach number.
Step-by-step explanation:
Vortex generators delay the formation of shockwaves by disturbing the airstream and generating small-scale vortices that mix high-energy air from the outer flow with the lower-energy air near the aircraft surface. This mixing action energizes the boundary layer and helps to delay flow separation and the resultant shockwaves that can lead to mach buffet, a condition characterized by unsteady airflow over an aircraft's wings at high speeds.
Sweepback, or angling the wings backward, also plays a role as it effectively reduces the wing's aspect ratio and delays the onset of shockwave-induced drag. Mach buffet typically occurs when an aircraft is flown at speeds close to or at the onset of transonic speeds, where airflow over parts of the wing reaches supersonic speeds causing shockwave formation and turbulent flow over the wing.
When flying from warm air to colder air, an aircraft must decrease its speed to maintain a constant Mach number because the speed of sound decreases in colder air, and the same Mach number represents a lower absolute speed in colder conditions.
A sonic boom is a result of the overlapping of all the sound waves that are produced by an aircraft as it travels faster than the speed of sound; however, the aircraft itself is frequently not visible because it has already passed by the point of observation before the slower-moving sound waves reaches the observer.