What is hooke's law

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.

the principle that the stress imposed on a solid is directly proportional to the strain produced, within the elastic limit

modulus of elasticity

The ratio of the stress applied to a body to the strain that results in the body in response to it. The modulus of elasticity of a material is a measure of its stiffness and for most materials remains constant over a range of stress. The ratio of the longitudinal strain to the longitudinal stress is called Young's modulus. The ratio of the stress on the body to the body's fractional decrease in volume is the bulk modulus. The ratio of the tangential force per unit area to the angular deformation in radians is the shear modulus.