Updated: 3/22/13 Sound and Light Energy Class Vocab List

Word Def PictureAbsorption When an object

collects the (light) energy and transforms it into heat.

Amplitude The height or strength of a wave, which determines volume.

Color Light property that depends on wavelength and frequency.

Compression When molecules are close together due to sound vibration

Concave lens Curved inward, spreads light out and forms smaller image that is right side up.

Concave Mirror

Inwardly curved mirror that will make image appear larger if up close to it. Upside down if farther away.

Convex lens Curved outward, bends light inward to focal point, flips image upside down if beyond focal point. Magnifies image if up close.

Convex Mirror

Outwardly curved mirror that will make image appear smaller

Cornea Outer layer of the eye that helps focus incoming light.

Crest Highest point in the wave (compression)

Decibel Unit of measurement for volume.

Density Object’s mass divided its volume (how close together the molecules are)

Diffraction Bending of light or sound waves around obstacles in its path.

Doppler Effect

Occurs when source of wave is moving toward or away from observer or visa versa. Coming toward you, the frequency & pitch increases. Going away from you, the frequency and pitch decrease

Ear Organ that funnels sound waves into the inner ear where sound energy is transformed into kinetic energy then transformed into electrical energy

Echo Sound wave bounces off surface and returns to its source.

Energy Ability to do work or cause change

Focal point Point where light rays converge into a single point.

Frequency Number of wave cycles that passes by a certain point in a period of time.

Heat Transfer of thermal energy, byproduct of all energy transformations.

Infrared Electromagnetic energy from the sun

Infrasonic Type of sound wave that is below 20 Hz

Intensity Amount of energy transmitted

Laser Light amplification simulated emission radiation.

Light Waves of electromagnetic energy or radiation

Light ray Beam of light traveling in a straight line away from its source

Light-year Distance light travels in one earth year

Longitudinal Waves

Waves of sound that go out in every direction that are caused by vibration of matter.

Luminous Referring to giving off light

Magnify To make something appear larger usually with one or more lenses.

Medium Any solid, liquid, or gas (matter) that sound can travel through

Opaque An object that light cannot travel through

Oscilloscope Instrument used to visualize sound waves

Pitch The high or low sound that is made by changing the frequency of the wave. High frequency = high pitch, low frequency = low pitch.

Polarization Waves of light from electromagnetic spectrum are restricted to a certain direction of vibration.

Prism Triangular piece of glass that separates white light into the spectrum of colors

Radiant energy

Energy that doesn’t need matter to travel.

Rarefaction Where (molecules) sound waves are spread apart. (trough of a sound wave)

Reflection To strike a surface and bounce back in opposite direction

Refraction When light is bent or changed when travelling through matter

Reverberation

When sound waves reflect

Sonar Use of reflected sound to detect objects.

Sound A vibration that travels through materials (air, liquid, solid) that you sense with your hearing

See sound waves

Sound wave Longitudinal energy waves that travel through matter

See longitudinal wave diagram

Speed of Light

186,000 miles/second300,000 Km/s

Speed of sound

Speed = distance divided by time.

Translucent Describes materials that allow some light to travel through.

Transmit Send energy from one place to another. Light or sound passes through an object.

Transparent Describes material through which light travels.

Trough Lowest point in the wave (rarefaction)

See rarefaction diagram

Ultrasonic Type of sound wave that is over 20,000 Hz

Ultraviolet Part of the electromagnetic spectrum (from the sun)

Vacuum Empty space where no molecules are present.

I can’t hear you!!!

Vibration Rapid movement of object back and forth causing sound.

Vocal Having to do with voice or speaking

See vocal chords

Vocal chord Structure of larynx that vibrates as air goes past it.

Volume Loudness or softness of sound related to amplitude of the wave

Wavelength Distance between two similar points on a wave.

Amplitude or crest diagrams.