Rigid or rigidity may refer to:
Mathematics and physics
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Stiffness
Stiffness is the extent to which an object resists deformation in response to an applied force.
The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
Calculations
The stiffness, k, of a b ...
, the property of a solid body to resist deformation, which is sometimes referred to as rigidity
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Structural rigidity, a mathematical theory of the stiffness of ensembles of rigid objects connected by hinges
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Rigidity (electromagnetism), the resistance of a charged particle to deflection by a magnetic field
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Rigidity (mathematics), a property of a collection of mathematical objects (for instance sets or functions)
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Rigid body, in physics, a simplification of the concept of an object to allow for modelling
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Rigid transformation
In mathematics, a rigid transformation (also called Euclidean transformation or Euclidean isometry) is a geometric transformation of a Euclidean space that preserves the Euclidean distance between every pair of points.
The rigid transformations ...
, in mathematics, a rigid transformation preserves distances between every pair of points
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Rigidity (chemistry), the tendency of a substance to retain/maintain their shape when subjected to outside force
*(Modulus of)
rigidity or shear modulus (material science), the tendency of a substance to retain/maintain their shape when subjected to outside force
Medicine
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Rigidity (neurology), an increase in muscle tone leading to a resistance to passive movement throughout the range of motion
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Rigidity (psychology), an obstacle to problem solving which arises from over-dependence on prior experiences
Other uses
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Real rigidity, and
nominal rigidity, the resistance of prices and wages to market changes in macroeconomics
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Ridgid
The Ridge Tool Company is an American manufacturing company that makes and distributes tools under the Ridgid brand name. The company was founded in 1923 in North Ridgeville, Ohio. In 1943, it relocated to its current location in Elyria, Ohio, ...
, a brand of tools
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