How fast it mach 1

As already noted, this is not a universal value, but comes down to the composition of the medium and the conditions of that medium. But even that is subject to variation. However, scientists tend to rely on the speed of sound as measured in dry air i. As with most ratios, there are approximations and categories that are used to measure the speed of the object in relation to the sound barrier. This gives us the categories of subsonic, transonic, supersonic, and hypersonic.

This categorization system is often used to classify aircraft or spacecraft, the minimum requirement being that most of the craft classified have the ability to approach or exceed the speed of sound. For aircraft or any object that flies at a speed below the sound barrier, the classification of subsonic applies.

This category includes most commuter jets and small commercial aircraft, though some exceptions have been noted i. Since these craft never meet or exceed the speed of sound, they will have a Mach number that is less than one and therefore expressed in decimal form — i.

Typically, these aircraft are propeller-driven and tend to have high aspect-ratio slender wings and rounded features. The designation of transonic applies to a condition of flight where a range of airflow velocities exist around and past the aircraft. These speeds are concurrently below, at, and above the speed of sound, ranging from Mach 0. Transonic aircraft nearly always have swept wings, causing the delay of drag-divergence, and are driven by jet engines.

The next category is supersonic aircraft. Aircraft designed to fly at supersonic speeds show large differences in their aerodynamic design because of the radical differences in the behavior of flows above Mach 1.

These include sharp edges, thin wing sections, and tail stabilizers aka. Craft that typically have this designation include modern fighter jets, spy planes like the SR Blackbird and the aforementioned Concorde. For example, the meteor that entered the skies above the above the small town of Chelyabinsk , Russia, in February of was traveling at a speed of about In other words, the meteorite was traveling between Mach 55 and 56 when it hit our atmosphere!

As an aircraft moves through the air, the air molecules near the aircraft are disturbed and move around the aircraft. If the aircraft passes at a low speed, typically less than mph, the density of the air remains constant. But for higher speeds, some of the energy of the aircraft goes into compressing the air and locally changing the density of the air.

This compressibility effect alters the amount of resulting force on the aircraft. The effect becomes more important as speed increases. But a sharp disturbance generates a shock wave that affects both the lift and drag of an aircraft.

The ratio of the speed of the aircraft to the speed of sound in the gas determines the magnitude of many of the compressibility effects.

Because of the importance of this speed ratio, aerodynamicists have designated it with a special parameter called the Mach number in honor of Ernst Mach , a late 19th century physicist who studied gas dynamics. The Mach number M allows us to define flight regimes in which compressibility effects vary.

There is no upstream influence in a supersonic flow ; disturbances are only transmitted downstream. The Mach number appears as a similarity parameter in many of the equations for compressible flows , shock waves , and expansions.

When wind tunnel testing, you must closely match the Mach number between the experiment and flight conditions.

The compressibility of the air alters the important physics between these two cases. The Mach number depends on the speed of sound in the gas and the speed of sound depends on the type of gas and the temperature of the gas.

The speed of sound varies from planet to planet. On Earth, the atmosphere is composed of mostly diatomic nitrogen and oxygen, and the temperature depends on the altitude in a rather complex way.