# Stability and States of Equilibrium

Show/Hide Sub-topics (Forces & Turning Effect Of Forces | O Level)

Stability refers to the ability of a body to restore to its original static equilibrium, after it has been slightly displaced.

## States of Equilibrium

### Stable Equilibrium

A equilibrium is said to be stable if small, externally induced displacements from that state produce forces or torques that tend to oppose the displacement and return the body to its original equilibrium.

Example: A hanging pendulum or a brick lying on a level plane.

### Unstable Equilibrium

An equilibrium is said to be unstable if the least departures produce forces or torques that tend to increase the displacement.

Example: A rule standing on its end or a ball standing on top of an inverted bowl.

### Neutral Equilibrium

An equilibrium is said to be neutral if small, externally induced displacements from that state does not produce any unbalanced forces or torques that tend to oppose or aggravate the displacement and the body remains in its new equilibrium.

Example: A ball or a pencil lying on a level surface.

## Criteria of Stable Bodies

Stable bodies tend to have:

Hence, the stablity of an object can be improved by:

• Lowering its centre of gravity
• Increasing the base area

### 4 thoughts on “Stability and States of Equilibrium”

1. THE NOTES ARE VERY USEFUL TO THE POINT AND I AM USING THEM TO PREPARE CANDIDATES FOR THEIR O’ LEVEL EXAMINATION IN PHYSICS.