Question

What is the example of unstable equilibrium?

Answer 1

Hint: As a very first step, one could define the term ‘equilibrium’. After that one could classify the equilibrium into three and also define each of them in order to understand how one is different from the other. Then could think of an example for unstable equilibrium as per its definition.

Complete answer:
In the question, we are asked to give an example for unstable equilibrium. First of all, we have to understand what is implied when the term ‘equilibrium’ is mentioned here. One should understand that equilibrium is the term that is used to define the stability of an object.
Another point to be noted here is that not everything that is in equilibrium is stable. In fact, equilibrium itself is classified into stable, unstable and neutral equilibriums.
When the body experiences a net force or torque in a certain direction which is opposite to the displacement’s direction, then the equilibrium is stable. When the equilibrium is found to be independent of displacements from its original position then the system is at neutral equilibrium.
When the body experiences a net force or maybe torque in the same direction as the displacement from equilibrium, then the system is at unstable equilibrium.
Example for unstable equilibrium would be: when an ice cream cone is placed at the apex on a book, the book’s movement would disturb the ice cream cone’s position.

Note: We could define unstable equilibrium for a body when this body doesn’t regain its original position on experiencing an external force. We have another definition for the same. When the imaginary line joining the centre of gravity with the centre of earth doesn’t lie on the same line is unstable equilibrium.