HOME TheInfoList.com
Providing Lists of Related Topics to Help You Find Great Stuff
 Cgs The centimetre–gram–second system of units (abbreviated CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time. All CGS mechanical units are unambiguously derived from these three base units, but there are several different ways of extending the CGS system to cover electromagnetism. The CGS system has been largely supplanted by the MKS system based on the metre, kilogram, and second, which was in turn extended and replaced by the International System of Units International System of Units (SI) [...More...] picture info Viscosity The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal concept of "thickness"; for example, honey has higher viscosity than water. Viscosity Viscosity is a property of the fluid which opposes the relative motion between the two surfaces of the fluid that are moving at different velocities. In simple terms, viscosity means friction between the molecules of fluid. When the fluid is forced through a tube, the particles which compose the fluid generally move more quickly near the tube's axis and more slowly near its walls; therefore some stress (such as a pressure difference between the two ends of the tube) is needed to overcome the friction between particle layers to keep the fluid moving [...More...] picture info Shear Stress A shear stress, often denoted τ (Greek: tau), is the component of stress coplanar with a material cross section. Shear stress Shear stress arises from the force vector component parallel to the cross section [...More...] picture info Mechanical Work W = F ⋅ s W = τ θPart of a series of articles aboutClassical mechanics F → = m a → displaystyle vec F =m vec a Second Second law of motionHistory TimelineBranchesApplied Celestial Continuum Dynamics Kinematics Kinetics Statics StatisticalFundamentalsAcceleration Angular momentum Couple D'Alembert's principle Energykinetic potentialForce Frame of reference Inertial frame of reference Impulse Inertia / Moment of inertia MassMechanical power Mec [...More...] picture info Newton's Laws Of Motion Newton's laws of motion Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces. More precisely, the first law defines the force qualitatively, the second law offers a quantitative measure of the force, and the third asserts that a single isolated force doesn't exist. These three laws have been expressed in several ways, over nearly three centuries, and can be summarised as follows:First law: In an inertial frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force.Second law: In an inertial reference frame, the vector sum of the forces F on an object is equal to the mass m of that object multiplied by the acceleration a of the object: F = ma [...More...] picture info Velocity The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of its speed and direction of motion (e.g. 7001600000000000000♠60 km/h to the north). Velocity Velocity is an important concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called "speed", being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s) or as the SI base unit of (m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector [...More...] picture info Derived Unit The International System of Units International System of Units (SI) specifies a set of seven base units from which all other SI units of measurement are derived. These SI derived units are either dimensionless, or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation. Many derived units do not have special names. For example, the SI derived unit of area is the square metre (m2) and the SI derived unit of density is the kilogram per cubic metre (kg/m3 or kg m−3). However, 22 derived units are recognized by the SI with special names, which are written in lowercase [...More...] picture info SI Derived Unit The International System of Units International System of Units (SI) specifies a set of seven base units from which all other SI units of measurement are derived. These SI derived units are either dimensionless, or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation. Many derived units do not have special names. For example, the SI derived unit of area is the square metre (m2) and the SI derived unit of density is the kilogram per cubic metre (kg/m3 or kg m−3). However, 22 derived units are recognized by the SI with special names, which are written in lowercase [...More...] picture info Astronomy Astronomy Astronomy (from Greek: ἀστρονομία) is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets; the phenomena include supernova explosions, gamma ray bursts, and cosmic microwave background radiation. More generally, all phenomena that originate outside Earth's atmosphere Earth's atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe Universe as a whole. Astronomy Astronomy is one of the oldest of the natural sciences [...More...] picture info Electrodynamics Classical electromagnetism Classical electromagnetism or classical electrodynamics is a branch of theoretical physics that studies the interactions between electric charges and currents using an extension of the classical Newtonian model. The theory provides an excellent description of electromagnetic phenomena whenever the relevant length scales and field strengths are large enough that quantum mechanical effects are negligible [...More...] picture info Material Science The interdisciplinary field of materials science, also commonly termed materials science and engineering is the design and discovery of new materials, particularly solids. The intellectual origins of materials science stem from the Enlightenment, when researchers began to use analytical thinking from chemistry, physics, and engineering to understand ancient, phenomenological observations in metallurgy and mineralogy. Materials science Materials science still incorporates elements of physics, chemistry, and engineering. As such, the field was long considered by academic institutions as a sub-field of these related fields [...More...] The Astrophysical Journal The Astrophysical Journal, often abbreviated ApJ (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale George Ellery Hale and James Edward Keeler [...More...] picture info Gradient In mathematics, the gradient is a multi-variable generalization of the derivative. While a derivative can be defined on functions of a single variable, for functions of several variables, the gradient takes its place. The gradient is a vector-valued function, as opposed to a derivative, which is scalar-valued. Like the derivative, the gradient represents the slope of the tangent of the graph of the function. More precisely, the gradient points in the direction of the greatest rate of increase of the function, and its magnitude is the slope of the graph in that direction. The components of the gradient in coordinates are the coefficients of the variables in the equation of the tangent space to the graph [...More...] picture info William Thomson, 1st Baron Kelvin William Thomson, 1st Baron Kelvin, OM, GCVO, PC, FRS, FRSE FRSE (26 June 1824 – 17 December 1907) was a Scots-Irish mathematical physicist and engineer who was born in Belfast Belfast in 1824. At the University of Glasgow Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging discipline of physics in its modern form. He worked closely with mathematics professor Hugh Blackburn Hugh Blackburn in his work. He also had a career as an electric telegraph engineer and inventor, which propelled him into the public eye and ensured his wealth, fame and honour. For his work on the transatlantic telegraph project he was knighted in 1866 by Queen Victoria, becoming Sir William Thomson [...More...] picture info Outline Of The Metric System The following outline is provided as an overview of and topical guide to the metric system: Metric system Metric system – various loosely related systems of measurement that trace their origin to the decimal system of measurement introduced in France during the French Revolution.Contents1 Nature of the metric system1.1 Essence of the metric system 1.2 Underlying philosophy2 Metric units of measure 3 History of the metric system3.1 Chronological history of the metric system 3.2 History of metrication 3.3 Historical metric system variants 3.4 History of [...More...] picture info One-to-one Correspondence In mathematics, a bijection, bijective function, or one-to-one correspondence is a function between the elements of two sets, where each element of one set is paired with exactly one element of the other set, and each element of the other set is paired with exactly one element of the first set. There are no unpaired elements. In mathematical terms, a bijective function f: X → Y is a one-to-one (injective) and onto (surjective) mapping of a set X to a set Y. A bijection from the set X to the set Y has an inverse function from Y to X. If X and Y are finite sets, then the existence of a bijection means they have the same number of elements [...More...]
.