A solid has definite shape and size. In order to change (or deform) the shape or size of a body, a force is required. If you stretch a helical spring by gently pulling its ends, the length of the spring increases slightly. When you leave the ends of the spring, it regains its original size and shape. Solids are not perfectly rigid. A rigid body generally means a hard solid object having a definite shape and size. But in reality, solid bodies can be stretched, compressed, and bent.

Properties of Solids:

Solids have a definite shape and size.
Solids are crystalline or amorphous.
The density of solids is slightly higher than their liquid states.

Elasticity: The property of a body by virtue of which, it tends to regain its original size and shape when the applied force is removed is known as elasticity and the deformation caused is known as elastic deformation. For example, Steel is an elastic body.

Plasticity: The body which has no tendency to regain its original shape and get permanently deformed is called plastic body. This property is known as plasticity. For example, clay, wax, etc. are plastic bodies

In this chapter, we shall study the elastic behaviour and mechanical properties of solids which would answer many such questions.

Previous Lesson

Back to Lesson

Next Topic