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The following is a list of speed records for various types of vehicles.This list only presents the single greatest speed achieved in each broad record category; for more information on records under variations of test conditions, see the specific article for each record category.
The refractive index of air is approximately 1.0003. [64] Denser media, such as water, [65] glass, [66] and diamond, [67] have refractive indexes of around 1.3, 1.5 and 2.4, respectively, for visible light. In exotic materials like Bose–Einstein condensates near absolute zero, the effective speed of light may be only a few metres per second.
Mach's suggestion can be taken as the injunction that gravitation theories should be relational theories. Einstein brought the principle into mainstream physics while working on general relativity. Indeed, it was Einstein who first coined the phrase Mach's principle. There is much debate as to whether Mach really intended to suggest a new ...
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):
Relativistic rocket means any spacecraft that travels close enough to light speed for relativistic effects to become significant. The meaning of "significant" is a matter of context, but often a threshold velocity of 30% to 50% of the speed of light (0.3c to 0.5c) is used.
The Lorentz factor γ is defined as [3] = = = = =, where: . v is the relative velocity between inertial reference frames,; c is the speed of light in vacuum,; β is the ratio of v to c,; t is coordinate time,
Its initial value is 1 when speed is zero and increases without bound as speed approaches light speed, c. Inverse of Lorentz factor as a function of speed, v, as a proportion of light speed, c - a circular arc.
Based on air resistance, for example, the terminal speed of a skydiver in a belly-to-earth (i.e., face down) free fall position is about 55 m/s (180 ft/s). [3] This speed is the asymptotic limiting value of the speed, and the forces acting on the body balance each other more and more closely as the terminal speed is approached.