Physics Lecture Review: Newton's Laws and Forces

Practice vocabulary flashcards defining key terminology, principles, and equations regarding Newton's laws of motion, contact forces, and friction.

Velocity

A kinematic quantity defined as distance divided by time, used to relate speed to the time required to complete a circular path.

Acceleration

The rate of change in velocity over time, appearing in equations that relate net applied forces to an object's mass.

Newton's First Law

A conceptual, non-quantitative law stating that an object at rest remains at rest, and an object in motion continues with the same velocity (speed and direction), unless acted upon by a net external force.

Newton's Second Law

A physical law stating that a net external force causes an acceleration proportional to that force and inversely proportional to mass, represented by summing all forces to equal mass times acceleration ($\sum F = ma$).

Free Body Diagram

A diagrammatic representation of an object used to isolate and label all individual external forces acting upon it before establishing coordinate equations.

Weight Force

The downward gravitational pull exerted on an object by the Earth, calculated directly as $mg$.

Normal Force

A contact force exerted by a surface that acts strictly perpendicular to the contact plane; it does not possess a fixed general formula and must be determined using Newton's second law.

Tension Force

A pulling force transmitted along a rope, string, or restraint that acts strictly in the direction and at the angle of that rope.

Static Friction

A contact force parallel to a surface that acts to prevent an object from beginning to slide, providing only as much opposing force as necessary until its threshold limit is reached.

Maximum Static Friction

The upper breaking-point threshold of static friction reached right before an object begins to slip, evaluated as $\mu_s F_n$.

Kinetic Friction

A resistive contact force that opposes motion and decelerates an object that is already sliding across a surface, calculated by the equation $f_k = \mu_k F_n$.

Newton's Third Law Pair

A pair of forces of the identical type where the force of object $A$ on object $B$ is equal in magnitude and opposite in direction to the force of object $B$ on object $A$.

Centripetal Acceleration

The acceleration experienced by an object following a curved or circular path, expressed mathematically as $\frac{v^2}{r}$.