1. Waves, Light, and Sound Vocabulary

2. WAVES Mechanical Waves: energy that travels through matter; examples include sound, ocean waves, and earthquake waves Electromagnetic Waves: form of energy that can travel through empty space as well as through matter; includes visible light, radio waves, x-rays, and many other wavelengths Hertz: Measurement of wave frequency equal to vibrations per second. Wavelength: distance from any point on one wave to a corresponding point on the next wave, such as crest to crest or compression to compression.

3. Waves Frequency: number of wave vibrations (oscillations) produced in one second, measured in hertz (Hz) Amplitude: total distance a wave moves (oscillates) from its resting position. Reflection: bouncing back of a wave from a surface; in light, reflection from a surface is specular reflection from a rough surface is diffuse reflection. Refraction: bending of a wave as it moves across the boundary between one medium and another.

4. Sound Longitudinal Wave: a wave that oscillates back and forth parallel to the direction it is traveling; where the wave pushes matter closer together is a compression; where the wave pushes matter farther apart is a rarefaction Compression: regions where the coils are closer in a longitudinal wave Rarefaction: regions where the coils are farther apart in a longitudinal wave Pitch: how high or low a sound is; determined by the sound wave’s frequency Decibels: Unit of measurement for the loudness of sound.

5. Light Transverse Wave: a wave that oscillates perpendicular to the direction it is traveling Crest: highest point of a transverse wave Trough: lowest point of a transverse wave Electromagnetic Spectrum: full range of electromagnetic waves

6. Light Law of Reflection: states that a wave bounces off a surface at the same angle that it hits the surface Transmission: passage of light through matter; also, sending of information or energy from one point to another Transparent: describes matter that allows light to pass through it easily Translucent: describes matter that allows some, but not all, of the light that hits it to pass through, and that scatters some light Opaque: describes matter that light does not pass through