The Solar System, Gravitation, and Modeling Mechanical Interactions

Vocabulary flashcards covering the organization of the solar system, the nature of gravitational attraction, categories of mechanical interactions, and the rules for modeling forces with vectors.

Solar System

A planetary system composed of a set of celestial objects (planets and their natural satellites, asteroids, comets) that all orbit around a single star: the Sun.

Terrestrial Planets

One of the two main categories of planets in the solar system, characterized by a rocky composition, with Earth being an example.

Gas Giants

One of the two main categories of planets in the solar system, distinct from rocky terrestrial planets.

Gravitation

An attractive, action-at-a-distance force that acts between any two objects that have mass, pulling planets toward the Sun.

Distance Dependency of Gravitation

A property of gravitational attraction stating that the force decreases when the distance between the two interacting objects increases.

Planetary Orbital Velocity

The speed of the planets that keeps them in orbit and prevents them from crashing directly into the Sun under the pull of gravity.

Action-at-a-Distance Interaction

An interaction exerted between two objects that do not touch each other, such as gravitation or magnetism.

Contact Interaction

An interaction that occurs only when two objects directly touch each other (e.g., kicking a ball or sitting on a chair).

Force Vector ($\vec{F}$)

A mathematical vector used to model and represent a mechanical interaction, characterized by an origin, a direction, and a sense.

Origin (of a Force Vector)

The point of application of the force, located at the center of the object that experiences or undergoes the force.

Direction (of a Force Vector)

The straight line passing through the centers of both interacting objects along which the force acts.

Sense (of a Force Vector)

The orientation along the line of action, pointing from the origin (the object experiencing the force) toward the center of the object exerting the force.

Newton ($N$)

The standard unit of measurement for force, denoted by the symbol $N$.

Object-Interaction Diagram

A schematic diagram used to identify and map all contact and distance interactions acting on and between chosen objects.

Gravitational Force Vector of Earth on a Satellite

A force vector whose origin is at the center of the satellite, whose direction is the line passing through the centers of Earth and the satellite, and whose sense is directed toward the center of Earth.