mechanical energy: The energy an object has from its motion and position.
electromagnetic waves: Waves of energy, like light and radio waves, that can travel through empty space.
thermal energy: The energy of moving particles in a substance.
radiation: Energy that travels as waves, even through empty space, like heat from the sun.
convection: Heat moving through a liquid or gas as warm material rises and cool material sinks.
conduction: Heat moving by direct touch from one thing to another.
electrical energy: Energy carried by moving electric charges.
electric circuit: A complete, closed path that electricity can flow through.
electrical device: Something that uses electricity to work, like a lamp or phone.
electric current: The flow of electric charge through a material.
voltage: The push that makes electric current flow, measured in volts.
resistance: How much a material slows the flow of electric current, measured in ohms.
geothermal energy: Energy from heat inside Earth.
solar energy: Energy from the sun.
wind energy: Energy from moving air, often captured by wind turbines.
hydroelectric energy: Electricity made from moving water, like water flowing through a dam.
seismic waves: Waves of energy that travel through Earth, often caused by earthquakes.
ocean waves: Waves that move energy across the surface of the ocean.
sound waves: Vibrations that travel through matter and that we hear as sound.
light waves: Electromagnetic waves that our eyes can see.
work: Using a force to move an object over a distance.
mechanical waves: Waves, like sound and water waves, that need matter to travel through.
medium: The material a wave travels through, like air or water.
vibration: A quick back-and-forth motion.
transverse wave: A wave that moves the medium up and down while the wave travels forward.
crest: The highest point of a wave.
trough: The lowest point of a wave.
longitudinal wave: A wave that pushes the medium back and forth in the same direction the wave travels, like sound.
rarefaction: The part of a longitudinal wave where particles are spread apart.
compression: The part of a longitudinal wave where particles are squeezed together.
speed: How far something travels in a certain amount of time.
wavelength: The distance from one crest to the next crest of a wave.
amplitude: How tall a wave is — how far it moves from its resting position. Bigger means more energy.
frequency: How many waves pass a point each second.
pitch: How high or low a sound is. More vibrations per second make a higher sound.
vacuum: Space with no matter in it, not even air.
uniform: The same all the way through.
electric potential: The electrical “push” at a point in a circuit, compared to another point. Voltage measures the difference.
voltmeter: A tool that measures voltage.
ammeter: A tool that measures electric current.
parallel circuit: A circuit with more than one path for current. If one bulb goes out, the others stay on.
series circuit: A circuit with only one path for current. If one bulb goes out, they all go out.

Warm-up words to review

Words from earlier grades that help with this unit.

density: How much mass is packed into a certain volume.

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