Newton’s Laws of Motion & Momentum (Sections 3.3 & 3.4) - Vocabulary

Vocabulary flashcards covering key concepts from Newton’s Laws of Motion and Momentum based on Sections 3.3 & 3.4.

Inertia

The tendency of matter to resist a change in motion; a body at rest stays at rest, and a body in motion tends to continue moving unless acted on by an unbalanced external force.

Newton's First Law (Law of Inertia)

A body at rest stays at rest, and a body in motion continues in motion at constant velocity unless acted on by an unbalanced external force.

Unbalanced External Force

A net external force that causes a change in an object's motion (not zero; can change speed or direction).

Mass

A measure of the amount of matter in an object; closely related to inertia.

Acceleration

The rate of change of velocity; directly proportional to force and inversely proportional to mass (F = ma).

Force

A push or pull on an object; causes acceleration and is measured in newtons (N).

Newton's Second Law

F = ma; acceleration increases with force and decreases with mass.

F = ma

The equation for Newton's Second Law: Force equals mass times acceleration.

Momentum

The quantity of motion of a body, p = mv; measured in kg·m/s; momentum is a vector.

p = mv

The formula for momentum: momentum equals mass multiplied by velocity.

Momentum as a Vector

Momentum has both magnitude and direction, determined by the object's velocity.

Conservation of Momentum

In a closed system with no external forces, the total momentum remains constant.

Third Law (Newton's Third Law)

For every action, there is an equal and opposite reaction; forces occur in pairs.

Action-Reaction Pair

A pair of equal and opposite forces exerted by two interacting objects on each other.

Newton (unit of force)

SI unit of force; 1 N = 1 kg·m/s².

External Force

A force applied from outside the system that can change an object's motion.

Net Force

The vector sum of all external forces acting on an object.