Physics Vocabulary

force a push or pull that causes an object to move, stop, or change direction a push or pull that causes an object to move, stop, or change direction

friction a force that slows or stops motion when two surfaces rub against each other

magnetism the attraction of an object containing iron to a magnet

gravitation the force that pulls all objects in the universe toward one another the force that pulls all objects in the universe toward one another

balanced forces forces acting on an object that are equal in size and opposite in direction, canceling each other out

unbalanced forces forces that are not equal; when one force is greater than its opposite force, the object’s motion changes forces that are not equal; when one force is greater than its opposite force, the object’s motion changes

energy  the ability to cause change in position or temperature

electric current  the constant flow of electrons from through a conductor

conductor  a material that conducts electricity easily

electric circuit  the path along which electricity can flow

insulator  a material that does not carry electricity

resistor  a material that resists the flow of electricity in some way

electromagnet  a temporary magnet made by passing electric current through a wire coiled around an iron bar

reflection  the light energy that bounces off objects

refraction  the bending of light rays when they pass through a substance

lens  a piece of clear material that bends, or refracts, light rays passing through it

temperature  the average kinetic energy of all the molecules in an object

Heat energy  the energy of moving particles in a substance

hydroelectric energy  electricity generated from the force of moving water

tidal energy  a form of hydroelectric energy that produces electricity from the rising and falling of tides

nuclear energy  the energy released when the nucleus of an atom is split apart

geothermal energy  heat from inside the Earth

solar energy  the energy of sunlight