Question

When is a body said to be perfectly elastic?

Answer 1

Hint Elasticity of an object is defined as the ability of that object or material to regain its normal shape after being stretched or compressed or any other deformation in its shape. Using this definition we can guess when a body is said to be perfectly elastic.

Complete step-by-step answer:
When a force is applied on a body, it’s shape always deforms. It can be compressed, stretched or any other type of deformation. After the force is removed from the body, then the measure or the ability of that object to regain its shape is its elasticity.

No matter what the body is, it can always be compressed, stretched or deformed upto a certain limit. After that limit, the body can be broken up.

Graphically, the elasticity of an object is described by a stress–strain curve, which shows the relation between stress. The curve is generally nonlinear, but it can be approximated as linear for sufficiently small deformations.

Hooke's law states that the force applied to an elastic object required to deform that elastic object should be directly proportional to the measure or distance of deformation, regardless of how large that distance becomes. This is known as perfect elasticity, in which that object will return to its original shape no matter how strongly it is deformed.

It means the body will be able to regain it’s totally original shape and dimensions which it had initially if the body is perfectly elastic.

Note A body is said to be perfectly elastic if that object totally regains its shape after a force is applied to it. No matter how much force is applied to that object and how much that object is deformed, stretched or compressed.