Final answer:
The 4 speed regimes are subsonic, transonic, supersonic, and hypersonic, each categorized by its typical speed ranges and applicable to different activities or vehicles, from walking to space travel.
Step-by-step explanation:
The 4 speed regimes refer to ranges of speed within various modes of travel and physics. Each regime is distinguished by its typical speeds and the environments in which those speeds are generally encountered.
- Subsonic: This regime includes speeds that are well below the speed of sound at sea level. Common examples include everyday activities such as walking (5 km/h), cycling (13-18 km/h), and driving under the rural speed limit.
- Transonic: This regime is around the speed of sound, and objects moving through this regime will experience different airflow characteristics due to the speed. This domain includes speeds just below to just above the speed of sound, which is approximately 343 meters per second at sea level.
- Supersonic: Speeds in this regime are faster than the speed of sound. Examples include the speeds achieved by the space shuttle on reentry, which typically exceeds Mach 5 (five times the speed of sound).
- Hypersonic: This regime comprises speeds greater than Mach 5. At this level, vehicles, such as some rockets or experimental aircraft, can achieve speeds like the official land speed record or even greater, such as reaching the escape velocity of Earth, which is about 11.2 kilometers per second.