Mach 5 refers to a speed that is five times the speed of sound in air, which is approximately 3,836 kilometers per hour (2,380 miles per hour) at sea level. This speed is significant in aerospace and military applications, as it allows for rapid travel and advanced maneuverability. Vehicles or aircraft that can achieve Mach 5 are often classified as hypersonic. Research and development in this area focus on improving propulsion systems and materials to withstand the extreme temperatures and pressures encountered at such high speeds.