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An object at height h above the ground and slant range R forms an angle α that can be calculated through sin α = h / R.By re-arrangement, R = h / sin α, or R = h csc α. The radar equation states that the signal received from an object, P e, varies inversely with the 4th power of range and directly as the square of the antenna gain, G, such that P e ~ G 2 / R 4.
mass density usually simply called density kilogram per cubic meter (kg/m 3) volume charge density: coulomb per cubic meter (C/m 3) resistivity: ohm meter (Ω⋅m) sigma: summation operator area charge density: coulomb per square meter (C/m 2) electrical conductivity: siemens per meter (S/m) normal stress: pascal (Pa)
Derived quantities can be expressed in terms of the base quantities. Note that neither the names nor the symbols used for the physical quantities are international standards. Some quantities are known as several different names such as the magnetic B-field which is known as the magnetic flux density , the magnetic induction or simply as the ...
The study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of laws and concepts of physics. physical constant physical quantity physics The natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force.
Although the SI unit of total cross sections is m 2, a smaller unit is usually used in practice. In nuclear and particle physics, the conventional unit is the barn b, where 1 b = 10 −28 m 2 = 100 fm 2. [1] Smaller prefixed units such as mb and μb are also widely used. Correspondingly, the differential cross section can be measured in units ...
In 1926, Wilhelm Lenz concluded that "If one allows waves of the shortest observed wavelengths λ ≈ 2 × 10 −11 cm, ... and if this radiation, converted to material density (u/c 2 ≈ 10 6), contributed to the curvature of the observable universe – one would obtain a vacuum energy density of such a value that the radius of the observable ...
The constants listed here are known values of physical constants expressed in SI units; that is, physical quantities that are generally believed to be universal in nature and thus are independent of the unit system in which they are measured.
(Also written as csc.) cosech – hyperbolic cosecant function. (Also written as csch.) cosh – hyperbolic cosine function. cosiv – coversine function. (Also written as cover, covers, cvs.) cot – cotangent function. (Also written as ctg.) coth – hyperbolic cotangent function. cov – covariance of a pair of random variables. cover ...