What is elasticity? Elasticity is explained in simple terms as the ability of a material or an object to resume its normal shape after being compressed or stretched. There is also a popular usage of the term in economics and business with a meaning matching to business scenarios. However, in physics, elasticity is the ability of something – say an object or a material – to resist a deforming or a distorting force and resume to its original shape and size.
Take the example of a rubber band. You can stretch the rubber band to a good length and when you leave the force on it, it will return to its original shape and size. So, rubber band is and elastic material.
During 17th century, when Robert Hooke, a physicist, studied about elasticity and springs noticed that the stress and strain curve of most solids have a linear relationship. He said, under given conditions, the force required to stretch an elastic object, like that of a spring, is directly proportional to the extension of the spring. His argument is popular as Hooke’s law and is expressed as:
F = -kx
where F is the force, k is a constant of proportionality and is also known as the spring constant, and x is the length of stretch or compression. The negative sign in the equation implies the restoring nature of the material or the object.
Well, this was only an introductory lesson on what is elasticity. A more advanced studies of linear elasticity and finite elasticity will be discussed later in our Young Scientist Premium Section. Meanwhile, you can see the effect of elasticity through the experiment – Bird in a cage.