Deformation

6a) state that a force may produce a change in size and shape of a body.

         A force can change both the size and shape of a body. This process is called deformation. Though we will mainly study only elastic deformation, this post covers the basics of elastic deformation as well as plastic deformation.

• Elastic deformation

        In elastic deformation, an object changes its size or shape when a force is applied on it. However, once the force stops acting on the object, the object returns to its original shape and position.
        Stretching a spring is a form of elastic deformation. You apply a force, and the size of the spring increases. However, once you stop applying the pulling force, the spring returns to its original shape.

• Plastic deformation

       In plastic deformation, an object is permanently damaged, and does not return to its original size or shape even when the force that caused the deformation stops acting on it.
       Stretching a spring is elastic deformation. However, you might have noticed that if you apply a force too large on the spring, and stretch it too much, the spring is permanently misshaped. Now, it won't return to its original size. This is an example of plastic deformation.