Apologia Physical Science Module 11

Universal Law of Gravitation

1. All objects with mass are attracted to one another by gravitational force. 2. The gravitational force between two masses is directly proportional to the mass of each object. 3. The gravitational force between two masses is inversely proportional to the square of the distance between those two objects.

Four Fundamental Forces of Creation (weakest to strongest)

1. Gravitational Force 2. Weak Force (weak nuclear interaction) 3. Electromagnetic Force (also called Lorentz force) 4. Strong Force (strong nuclear interaction)

Solar Wind

A "wind" resulting from particles being pushed away from the sun

Comet

A ball composed of dirt, dust grains, and "ice," that rotate around the sun in an elliptical orbit

Ceres

A dwarf planet that exists inside the asteroid belt

Eris

A dwarf planet that is larger than pluto

Gravitational Force

A force that attracts all objects that have mass

Weak Force

A force that governs radioactive processes in atoms

Strong Force

A force that is responsible for holing together the center (nucleus) of an atom

Electroweak Force

A force which the electromagnetic force and the weak force are both facets of

Pluto

A former official planet, which is now recognized as a dwarf planet

Oort Cloud

A hypothesis suggesting a large shell of icy bodies explaining where certain (long-period) comets came from

Graviton

A hypothetical tiny particle that two massive objects exchange

Tail (of a comet)

A long, glowing line of gases from the coma

Meteorite

A piece of a meteor that has fallen to the ground

Dwarf Planet

A small unofficial planet that orbits around the sun

Kuiper Belt

A smaller band of comet material existing just beyond Neptune and the source of short-period comets

General Theory of Relativity

A theory that is a broad explanation of an entire way of looking at physics and what causes gravitational force; According to the GTofR, gravity is not a force but a result of how mass bends space and time.

Perturbation

A variation in the motion of an object in space

Geocentric View of the Solar System

A view of the solar system that places the earth at the center of the solar system

Heliocentric View of the Solar System

A view of the solar system that places the sun at the center of the solar system

Meteor

An asteroid that has entered earth's atmosphere, burning up in white-hot flames due to friction

Meteoroid

An asteroid that has intersected earth's orbit, but nothing more

Electromagnetic Force

An attractive or repulsive force against objects with electrical charge

Universal Law of Gravitation Formula

An equation developed by Newton that allows physicists to calculate the strength of gravitational force between two objects

Satellite

An object that orbits around a planet

Solar System

An orderly arrangement of planets and their moons

Short-Period Comets

Comets that take less than 200 years to make an orbit; the Kuiper belt is considered a source for these comets.

Long-Period Comets

Comets that take more than 200 years to make an orbit; originates from the Oort Cloud

Very Long-Period Comets

Comets that take more than 5,000 years to make an orbit

Planetary Rings

Small bodies of rock, ice, and frozen gases encircling a planet in the form of a ring

Nucleus (Atom)

The center of an atom, containing protons and neutrons

Centripetal Force

The force necessary to make an object move in a circle. It is directed perpendicular to the velocity of the object, which makes it point to the center of the circle

The Galilean Satellites

The four biggest of Jupiter's satellites discovered by Galileo (Io, Europa, Castillo, and Ganymede)

Inner Planets

The four planets of our solar system closer to the sun than the asteroid belt (Mercury, Venus, Earth, and Mars)

Outer Planets

The four planets of our solar system farther from the sun than the asteroid belt (Jupiter, Saturn, Uranus, and Neptune)

Coma

The fuzzy atmosphere around the comet

Asteroid Belt

The region of our solar system containing the highest concentration of asteroids

Centripetal Acceleration

The resulting acceleration from centripetal force

Nucleus (Comet)

The solid part of a comet

Period (of a comet)

The time it takes for a comet to orbit the sun

Sublimate

To change from solid to gas (skipping the liquid state)