Forces and Motion

6.P.1.1 Compare the properties of waves to the wavelike property of energy in earthquakes, light and sound.6.P.1.2 Explain the relationship among visible light, the electromagnetic spectrum, and sight.6.P.1.3 Explain the relationship among the rate of vibration, the medium through which vibrations travel, sound and hearing.

Essential Vocabulary

WaveA moving disturbance that transfers energy through matter or space.

Transverse WavesA type of mechanical wave in which the wave energy causes matter in the medium to move up and down or back and forth at right angles to the direction the wave travels.

Longitudinal WavesA wave that causes the particles of the medium to vibrate parallel to the direction the wave travels.

Potential EnergyStored energy that results from the position or shape of an object.

TroughThe lowest point of a transverse wave.

CrestThe highest point of a transverse wave.

TimeAn interval separating two points of this quantity; a duration.

PeriodThe time required for one full wavelength to pass a certain point.

AmplitudeThe distance from the crest (or trough) of a wave to the rest position of the medium.

FrequencyThe number of complete wavelengths that pass a point in a unit of time.

WavelengthThe distance between a point on one wave and the identical point on the next wave.

RarefactionThe area of a longitudinal wave where the molecules are the most spread apart.

ReflectionThe bouncing back of a wave when it hits a surface or boundary.

DiffractionThe bending of a wave as it passes an edge or an opening.

InterferenceThe combination of two or more waves that exist in the same place at the same time.

Constructive Interference Any interference in which waves combine so that the resulting wave is bigger than the original waves.

Destructive InterferenceAny interference in which waves combine so the resulting wave is smaller than the largest of the original waves.

CompressionThe area of a longitudinal wave where the molecules are the most crowded together.

Seismic WavesEarthquake waves, including primary waves, secondary waves, and surface waves.

Electromagnetic WaveA wave caused by a disturbance in electric and magnetic fields. This sort of wave does not require a medium; also called a light wave.

EM SpectrumThe range of all possible frequencies of electromagnetic radiation.

Visible LightElectromagnetic radiation that can be seen with the unaided eye.

EnergyThe ability to do work or cause change.

SoundVibrations that travel through the air or another medium and can be heard when they reach a person's or animal's ear.

VibrationTo move back and forth.

MediumThe matter through which a wave travels.

VacuumA place that is empty of all matter.

PitchPerception of the frequency of a sound.

HertzThe unit of frequency; one hertz has a periodic interval of one second.

Speed/Wave SpeedA measurement of how fast a wave passes through a medium.

IntensityThe amount of energy per second carried through a unit area by a wave.

Decibel (dB)A unit used to compare the loudness of different sounds.

AmplificationIncrease the volume of; "amplify sound."

AcousticsThe study of how sounds interact with each other and the environment.

EcholocationThe use of reflected sound waves to determine distances or to locate objects.

SonarA device that determines the distance of an object under water by recording echoes of sound waves.

UltrasoundSound waves with frequencies above 20,000 Hz.

Doppler EffectAn observed change in the frequency of a wave when the source or observer is moving.

Mechanical WaveA wave that requires a medium through which to travel.

RSA unit of radiation exposure.

Law of ResonanceIf an object vibrates at a certain rate of vibration, everything in its vicinity that has the same vibration as a dormant possibility will start vibrating at that frequency.

EM Wave Electromagnetic radiation (often abbreviated E-M radiation or EMR) is a phenomenon that takes the form of self-propagating waves in a vacuum or in matter.

Radio WavesA type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light.

MicrowavesA radio wave of very high frequency and short wavelength.

UV LightElectromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays.

Infrared Light

The wavelength of light produced above the visible part of the spectrum.

X-Rays

Electromagnetic radiation of short wavelength produced when high-speed electrons strike a solid target.

Gamma Rays

Penetrating electromagnetic radiation of shorter wavelength than X-rays.

Prism

Optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image.

Primary Pigments

Sets of colors that can be combined to make a useful range of colors.

Primary Colors

Three colors that can be used to make any other color.

Optics

The branch of physics that studies the physical properties of light.

Image

A copy of an object formed by reflected or refracted rays of light.

ConvexCurving or bulging outward.

ConcaveCurving inward.

Focal PointThe point at which light rays parallel to the optical axis meet, or appear to meet, after being reflected (or refracted) by a mirror (or a lens).

LensA curved piece of glass or other transparent material that is used to refract light.

Focal LengthThe distance between the center of a lens or curved mirror and its focus.

CorneaThe transparent front surface of the eye.

PupilThe opening in the center of the iris through which light enters the inside of the eye.

Retina A layer at the back of the eyeball containing cells that are sensitive to light and that trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.

Optic NerveShort, thick nerve that carries signals from the eye to the brain.

Cones

Cells in the retina that respond to and detect color.

RodsCells in the retina that detect dim light.

The End!!!