Stability, Inertia, Center of Gravity, and Impact Mechanics (Video Notes)

Vocabulary flashcards covering key concepts from the video notes on inertia, center of gravity, stability, and impact mechanics.

Inertia

The resistance of any object to a change in its state of motion or rest; proportional to the object's mass.

Mass

The amount of matter in an object; determines inertia; more mass generally means greater resistance to changes in motion.

Center of Gravity (COG)

The point in space where the body's mass can be considered concentrated; its location varies with posture and body distribution.

Base of Support (BOS)

The area of contact between the body and the supporting surface; a wider BOS provides greater stability.

Stability

The ability to maintain balance; depends on the relationship between the center of gravity and the base of support.

Low Center of Gravity

A posture where the mass is closer to the ground; increases stability by expanding the effective BOS relative to COG.

High Center of Gravity

A posture where the mass is high above the ground; decreases stability and makes toppling easier.

Newton's Third Law (Action–Reaction)

For every action, there is an equal and opposite reaction; governs forces during impact and contact.

Momentum

The product of mass and velocity (p = m·v); a moving object's resistance to being stopped depends on its momentum.

Impulse

The change in momentum resulting from a force acting over time; longer contact time can reduce peak force.

Peak Impact Force

The maximum force experienced at the moment of impact; higher for rigid, undeformable contacts and lower when deformation spreads the load.

Deformation

A change in shape of a body under load; deformation can spread force over time and area, reducing peak impact.

Surface Area / Contact Area

The area over which a force is distributed; larger contact area lowers the stress (force per area) during impact.