If we apply a force on an object then it will lose original shape and get different shape. And if we remove the force which we applied then the object will get original shape, the property which the object have called Elasticity.
If we use the maximum value of deforming force on an object then it shows elastic property up to a certain limit, after that it will break out. This maximum limit of elasticity which the object shows, called Elastic limit.
Pressure or tension exerted on a material object per unit area set up inside the body is called stress.
If we apply a force on an object then the object will get dimension. This phenomena the relative change in shape of an object is called strain.
It is measured by ratio of change in length and volume to original values.
When we apply a force on an object then the shape of the object will be changed, which means stress is always proportional to strain under elastic limit this property is called as Hooke’s law.
Stress/ Strian = E ( Constant )
E is called as elastic constant or modulus of elasticity.
The value of E differ from material to material.
Units in SI system are Nm-2 and it is also called as Pascal.
Elastic constant (E) is of three types:
* Rigidity modulus (η) = Tangential stress / Shear stain
* Bulk modulus of elasticity (K) = Volume stress / Volume strain
* Young’s modulus of elasticity (Y) = Longitudinal stress / Longitudinal strain