Unstable equilibrium

Definition

Unstable equilibrium occurs when an object, if slightly displaced, tends to move further away from its original position. This type of equilibrium is sensitive to perturbations and does not return to its initial state.

5 Must Know Facts For Your Next Test

1. An object in unstable equilibrium has a high center of mass relative to its base of support.
2. Small disturbances cause the object to move further from its equilibrium position.
3. Examples include a pencil balanced on its point or a ball on top of a hill.
4. In terms of potential energy, unstable equilibrium corresponds to a local maximum.
5. Mathematically, the second derivative of the potential energy with respect to position is negative at unstable equilibrium points.

Review Questions

• What happens to an object in unstable equilibrium when it is slightly displaced?
• How can you identify an unstable equilibrium point using the concept of potential energy?
• Provide an example of an object in unstable equilibrium.

Related terms

Stable Equilibrium: A condition where an object returns to its original position after being slightly displaced.

Neutral Equilibrium:

A condition where an object remains in its new position after being slightly displaced.

Torque:

A measure of the force that can cause an object to rotate about an axis.