Elasticity (physics)

Something that is elastic can be stretched or deformed (changed) and returned to its original form, like a rubber band. It tries to come back to its first shape. The stress is the force applied; the strain is how much the shape is changed, and the elastic modulus is the ratio between those numbers.

Mechanics

Laws Conservation of mass Conservation of momentum Conservation of energy Entropy inequality Solid mechanics Solids Stress · Deformation Compatibility Finite strain · Infinitesimal strain Elasticity (linear) · Plasticity Bending · Hooke's law Failure theory Fracture mechanics Frictionless/Frictional Contact mechanics Fluid mechanics Fluids Fluid statics · Fluid dynamics Surface tension Navier–Stokes equations Viscosity: Newtonian, Non-Newtonian Rheology Viscoelasticity Smart fluids: Magnetorheological Electrorheological Ferrofluids Rheometry · Rheometer Scientists Bernoulli · Cauchy · Hooke Navier · Newton · Stokes

A rubber band is elastic, and can be stretched

Economic elasticity is at elasticity (economics)

This idea was first suggested by Robert Hooke in 1675.

The simplest model for elasticity is Hooke's law. It says that the force to stretch something (F) is proportional to the distance it is stretched (x). This is usually written as [math]\displaystyle{ F=k x }[/math], where [math]\displaystyle{ k }[/math] is a constant called the spring constant. If it is easy to stretch a material, that material has a lower k value.

Elastic materials are different than plastic materials. A plastic material can be stretched or deformed, but it will not return to its original form.