Something that iselastic can be stretched or deformed (changed) and returned to its original form, like arubber band. It tries to come back to its first shape. Thestress is the force applied; thestrain is how much the shape is changed, and theelastic modulus is the ratio between those numbers.
The simplest model for elasticity isHooke'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, where is aconstant called the spring constant. If it is easy to stretch amaterial, that material has a lower k value.
Elastic materials are different than plastic materials. Aplastic material can be stretched or deformed, but it will not return to its original form.
