Definition
Ratio of pressure (stress) applied to a body to the resistance (strain) produced by the body. If it is the ratio of longitudinal stress to strain, it is called Young's modulus. If it is the ratio of stress to the fractional decrease in the volume of the body, it is called bulk modulus. If it is the ratio of tangential force per unit area to the angular deformation (in radians) of the body, it is called modulus of rigidity, rigidity modulus, or shear modulus.
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