Energy and Waves Grade 6 Vocabulary

Comprehensive practice vocabulary flashcards covering wave properties, electromagnetic waves, human hearing mechanisms, heat transfer methods, and wave interactions for Grade 6 Physical Science.

Wave

A repeating disturbance that carries energy as it moves through a medium from one place to another.

Transverse Wave

A wave that moves side-to-side or up and down as it travels, displacing the particles of the medium in directions perpendicular to the direction the wave is moving.

Longitudinal Wave

A wave that alternately compresses and spreads out the material it travels through, displacing particles back and forth parallel to the direction of wave travel.

Crest

The highest point or peak of a wave.

Trough

The lowest point of a wave.

Amplitude

The distance measured from the center point (or rest point / zero line) of a wave to its highest point (crest) or lowest point (trough).

Wavelength

The distance over which a wave's complete shape repeats, such as from one crest to the adjacent crest or from one trough to the adjacent trough.

Cycle

One complete wave shape, ending at the same relative position where it began and repeating consecutively.

Period

The amount of time it takes for a wave to complete one full cycle or for a wave's shape to repeat.

Frequency

The number of complete cycles of a wave that occur in a given amount of time, commonly stated as the number of cycles per second.

Hertz ($\text{Hz}$)

The scientific unit used to measure wave frequency, named after Heinrich Hertz, where $1\,\text{Hz}$ equals $1\,\text{cycle per second}$.

Compression

A region in a longitudinal wave where particles of the medium are pressed tightly together.

Rarefaction

A region in a longitudinal wave where particles of the medium are spread apart and least dense.

Primary Waves (P-waves)

The fastest-moving earthquake waves; these longitudinal waves radiate out first from the location where tectonic plates move relative to each other.

Secondary Waves (S-waves)

The second earthquake waves to arrive, occurring seconds after primary waves; these are transverse waves that move the ground up and down.

Rayleigh Waves

The slowest-moving and most destructive earthquake waves, producing both the side-to-side motions of a longitudinal wave and the up-and-down motions of a transverse wave.

Electromagnetic Waves

Transverse waves comprised of fluctuating electrical and magnetic energy that travel through space at the speed of light ($299.8\,\text{million meters per second}$).

Visible Light

The narrow band of the electromagnetic spectrum that human eyes can see, spanning wavelengths from approximately $400\,\text{nanometers}$ (violet) to $700\,\text{nanometers}$ (red).

White Light

Light that is composed of all the wavelengths in the visible spectrum combined together.

Color Filter

A transparent material that allows only its own specific color of light to pass through while absorbing all other colors.

Diffraction Grating

An optical tool that breaks white light into its component colors and produces a visible spectrum.

Eardrum

A thin, sensitive membrane stretched across the entrance to the middle ear that vibrates when struck by sound waves and passes vibrations to the middle ear bones.

Hammer Bone

One of the three tiny bones in the middle ear; it is attached to the eardrum and passes vibrations received from the eardrum to the anvil bone.

Anvil Bone

The middle ear bone situated between the hammer and stirrup bones that receives vibrations from the hammer and transmits them to the stirrup.

Stirrup Bone

The smallest bone in the human body; located in the middle ear, it receives vibrations from the anvil and transmits them into the fluid of the inner ear.

Cochlea

A fluid-filled, snail-shaped sack in the inner ear containing hair cells that convert liquid vibrations into electrical nerve signals sent to the brain.

Auditory Nerve

The cranial nerve that transmits sound information and impulses from the hair cells of the cochlea to the brain.

Eustachian Tube

A canal connecting the middle ear to the back of the nose that equalizes air pressure with the atmosphere and drains fluid from the middle ear.

Tinnitus

A hearing condition characterized by a persistent ringing sound with no external acoustic source, often resulting from damaged cochlear hair cells.

Conduction

The transfer of heat between and through materials in direct physical contact as vibrating molecules repeatedly bump into adjacent molecules.

Convection

The transfer of heat through fluids (liquids or gases) that occurs when warmer, less dense fluid floats upward while cooler, denser fluid sinks.

Radiation

The transfer of heat energy through space via electromagnetic waves (such as infrared and visible light) without requiring direct contact or a physical medium.

Thermal Insulator

A material that conducts heat poorly, such as wood, plastic, rubber, or cloth pot holders.

Thermal Equilibrium

The balanced state reached when heat flows from warmer objects to cooler objects until both attain the same temperature.

Light Absorption

The process where matter takes in light energy striking its surface and converts it into heat or other energy forms.

Light Reflection

The process where light waves bounce off the surface of an object rather than passing through or being absorbed.