Question

What do you mean by the equilibrium of a body?

Answer 1

Body in equilibrium:

1. A state of the body where neither the internal energy nor the motion of the body changes with respect to time is called equilibrium.
2. When a number of forces acting on a body produce no change in its state of rest or of motion the body is said to be in equilibrium.
3. At equilibrium, the net force acting on the body is $0$.

Therefore, a body in equilibrium has zero resultant of all the external forces acting on it.