Ch. 20 Sec. 3 Wave Interactions & Behaviors Unit 4 Waves Ch. 20 Sec. 3 Wave Interactions & Behaviors

Reflection reflection - occurs when a wave strikes a surface & bounces off reflected sound = echo reflected light = image in a mirror and color

Refraction refraction - the bending of a wave as it moves from one medium to another occurs b/c the wave’s speed changes the “normal” is an imaginary line perpendicular to the surface of water when light passes from air to water, light slows down & bends toward “normal “ when light passes from water to air, light speeds up & bends away from “normal”   refraction causes… prisms to separate sunlight into many colors water droplets to separate sunlight into rainbows

Diffraction diffraction - the bending of waves around a barrier diffraction is greater when wavelength is similar in size to the barrier or opening where it passes ex. sound waves diffract through a doorway more than light b/c sound has longer wavelengths (closer to size of opening)

Interference interference - when 2 waves overlap & combine forming a new wave after they overlap, they continue traveling on their original paths

Types of Interference Constructive Destructive constructive interference occurs when waves meet & overlap crest to crest the 2 amplitudes temporarily combine making a larger wave destructive interference occurs when waves meet & overlap crest to trough the 2 amplitudes temporarily combine making a smaller wave

Waves Type: Mechanical Waves Electromagnetic Properties Behavior Requires a medium (cannot move through space) Transverse Compressional Ex. Sound Waves Electromagnetic Does not require a medium (can move through space) Ex. Radio Waves Ex. Ultraviolet Waves Ex. Visible Light Behavior Reflection Refraction Diffraction Interference Properties Wavelength Frequency Amplitude Speed