STABILITY

Stability

The property of a body that causes it to return to its original position or state of motion as a result of the action of restoring forces once its equilibrium has been disturbed.

Factors Affecting Stability1. Base of Support2. Location of The Center of Gravity3. Mass4. Line of Gravity

Base of Support• The area in contact with the

supporting surface plus the intervening area

• Wider base of support means greater stability

Location of Center of Gravity

• The point where the weight of the body is concentrated; the point where a body may be hung without rotating.

• Center of gravity must be as low as possible for greater stability.

Mass

• The amount of matter in a body.• Greater mass means greater inertia.• Body must be heavy for greater

stability.

Line of Gravity

• The vertical line passing through the center of gravity.

• Line of gravity must pass within the base of support for greater stability.

Types of Mechanical Equilibrium(States of Equilibrium )

Any object that is not accelerating may be in one of three states of equilibrium:

• Stable• Unstable• Neutral

Stable Equilibrium

• wide base of support• low center of gravity• heavy mass• line of gravity that passes within the base of support

Stable objects are characterized by:

The body returns to its original position once the disturbing force has been removed.

Unstable Equilibrium

• narrow base of support• high center of gravity• light mass• line of gravity that passes outside the base of support

Unstable objects are characterized by:

When a disturbing force is applied, the body falls over and seeks a different position.

Neutral Equilibrium

• circular and spherical bodies• a center of gravity that is neither lowered nor raised when

the object is toppled• bodies that roll on their sides

Neutral objects are characterized by:

When a disturbing force is applied, the body is displaced but its center of gravity remains in the same level.

What’s my type?

Stable, unstable, neutral?