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The transonic speed range is that range of speeds within which the airflow over different parts of an aircraft is between subsonic and supersonic. So the regime of flight from Mcrit up to Mach 1.3 is called the transonic range. Supersonic: 1.2–5.0 794–3,308 915–3,806 1,470–6,126 410–1,702
where a 0 is 1,225 km/h (661.45 kn) (the standard speed of sound at 15 °C), M is the Mach number, P is static pressure, and P 0 is standard sea level pressure (1013.25 hPa). Combining the above with the expression for Mach number gives EAS as a function of impact pressure and static pressure (valid for subsonic flow):
Gamma is exactly 5/3 = 1.667 for monatomic gases (such as argon) and it is 4/3 = 1.333 for triatomic molecule gases that, like H 2 O, are not co-linear (a co-linear triatomic gas such as CO 2 is equivalent to a diatomic gas for our purposes here); T is the absolute temperature; M is the molar mass of the gas. The mean molar mass for dry air is ...
Airspeed is commonly given in knots (kn). Since 2010, the International Civil Aviation Organization (ICAO) recommends using kilometers per hour (km/h) for airspeed (and meters per second for wind speed on runways), but allows using the de facto standard of knots, and has no set date on when to stop.
G is the universal gravitational constant (G ≈ 6.67 × 10 −11 m 3 ⋅kg −1 ⋅s −2 [4]) g = GM / d 2 is the local gravitational acceleration (or the surface gravity , when d = r ). The value GM is called the standard gravitational parameter , or μ , and is often known more accurately than either G or M separately.
Speed limit sign in the Republic of Ireland, using "km/h.". The SI representations, classified as symbols, are "km/h", "km h −1" and "km·h −1".Several other abbreviations of "kilometres per hour" have been used since the term was introduced and many are still in use today; for example, dictionaries list "kph", [3] [4] [5] "kmph" and "km/hr" [6] as English abbreviations.
vehicle-kilometre (vkm [1]) as a measure of traffic flow, determined by multiplying the number of vehicles on a given road or traffic network by the average length of their trips measured in kilometres. [2] vehicle-mile (vehicle miles traveled, or VMT [1]) same as before but measures the trip expressed in miles.
3.2808 The metre per second is the unit of both speed (a scalar quantity ) and velocity (a vector quantity , which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in a time of one second .