Introduction Mach number is a fundamental concept in aerodynamics and aviation, defining the speed of an object relative to the speed of sound. It is named after Austrian physicist Ernst Mach and plays a crucial role in understanding aircraft performance, supersonic travel, and aerodynamics. A high-quality, realistic illustration of an aircraft breaking the sound barrier, showcasing the concept of Mach number, supersonic speed, and shock waves in aerodynamics. What is Mach Number? Mach number ( M ) is a dimensionless unit representing the ratio of an object's speed to the speed of sound in a given medium. It is expressed as: M = V a M = \frac{V}{a} M = a V ​ where: M = Mach number V = Velocity of the object a = Speed of sound in the medium The speed of sound varies based on temperature and altitude. At sea level (15°C), the speed of sound in air is approximately 343 m/s (1235 km/h or 767 mph) . Mach Number Classifications Aircraft and objects traveling at different Mach speeds...