The New Student's Reference Work/Hooke's Law

Hooke's Law describes an important phenomenon of elasticity, namely, that when a rod or wire of any material is stretched by a force, the elongation of the wire varies directly as the force. This law, which was discovered by Robert Hooke in 1675, holds only for those cases in which the forces are not so great as to exceed the limits of elasticity of the material. Hooke's law is now employed in a still more general sense to mean that the ratio of stress to strain is, within limits, a constant for all kinds of strains. See Elasticity.