Hooke's law

A law stating that the stress applied to a material is proportional to the strain on that material. For example, if a stress on a metal bar of ten newtons per square centimeter causes it to be compressed by four millimeters, then a stress of 20 newtons per square centimeter will cause the bar to be compressed by eight millimeters. Hooke's law generally holds only up to the elastic limit of stress for that material.

See also modulus of elasticity