Laws of Motion

Vocabulary flashcards covering key terms and definitions from the Laws of Motion notes.

Isaac Newton

English scientist and mathematician who developed Newton's laws of motion and the universal law of gravitation; lived 1643–1727 and published Principia.

Principia Mathematica

Short for Philosophiae Naturalis Principia Mathematica; Newton's 1687 work presenting four scientific laws and gravitational theory.

Philosophiae Naturalis Principia Mathematica

Latin title of Newton's major work; commonly called Principia.

Universal law of gravitation

Newton's law describing gravity as the force governing the motion of planets and objects.

Newton's laws of motion

The set of laws describing the relationship between forces and motion of objects.

Force

A push or pull on an object; can cause acceleration or a change in direction; described by magnitude and direction and measured in newtons.

Exert

To apply or put forth a force on an object.

Newton (unit)

SI unit of force, named after Isaac Newton.

Acceleration

The change in an object's velocity due to a net force.

Force pair

Two forces in Newton's third law that act on different objects and are equal in strength but opposite in direction.

Newton's third law of motion

When one object exerts a force on another, the second object exerts an equal and opposite force on the first.

Equal and opposite forces

Forces in a force pair that are equal in magnitude and opposite in direction.

Geocentric model

Earth-centered view of the solar system; reflects old ideas before Copernicus.

Copernicus

Polish astronomer who proposed a heliocentric solar system.

Kepler

German astronomer who announced three laws describing planetary motion.

Galileo Galilei

Italian scientist whose work on motion and astronomy influenced Newton.

Scientific law

A concise statement or mathematical description of a natural phenomenon; unlike theories, laws do not explain why it happens.

Scientific theory

An explanation supported by evidence; explains phenomena, unlike a law.

Model

A mathematical or conceptual description used to describe planetary motion and other phenomena.

Force magnitude

The strength of a force; indicated by the length of its arrow in a force diagram; measured in newtons.

Force direction

The direction in which a force acts; indicated by the arrow's orientation.

Interaction

Forces occur when two objects interact with each other.

Pendulum demonstration

Experiment showing equal and opposite forces when pendulums collide, illustrating Newton's third law.

Heliocentric model

Sun-centered model of the solar system supported by Copernicus and Kepler.

Force vector

Graphical representation of a force using an arrow; length shows magnitude and direction shows the force direction.