What happens to a rubber band when you stretch it and let go? It deforms but regains its original nature when you stop applying a force. But say, you take an aluminium rod and try to bend it using your arm strength. You somehow do manage to bend it a little and then stop applying force. Does the rod regain its original shape? Of course not.
This difference in the behaviour of the material is based on their elastic and plastic nature. The rubber band has high elasticity. Elasticity is the ability of a body to resist any permanent changes to it when stress is applied. The body regains its original shape and size when stress application ceases.
Important Points on Elastic Behaviour Of Solids
- An elastic body is one that regains its original shape and size when deforming forces are removed
- A plastic body is one that succumbs to deforming forces (however small) and cannot return to its original shape and size
- Elasticity is the property of a body to regain its original shape and size when deforming forces are removed. It exhibits an opposition to change.