Wave Interaction

All are transmitting/carrying ENERGY, not matter What is a Medium?? A medium is the substance that the wave is traveling through Examples: a wave could be traveling through water, air, solid earth, etc. Sound travels through air Waves in the ocean travel through water Waves produced by an earthquake travel through solid earth All are transmitting/carrying ENERGY, not matter

Reflection: waves bouncing back toward original source A mirror image is light waves reflecting (why we call it your reflection) An echo is sound wave reflecting back http://www.acoustics.salford.ac.uk/schools/teacher/lesson3/flash/whiteboardcomplete.swf

Refraction: Waves bending prisms bend light differently according to wavelength Happens when waves change mediums (water to air) Refraction coefficient (math way to figure out bending angle)

Amount of diffraction depends on wavelength Diffraction: the bending of waves around a barrier or through an opening This is why you hear sound (music, voices, etc.) even when you are in another room-sound waves (long wavelength) are able to diffract around corners Amount of diffraction depends on wavelength http://www.launc.tased.edu.au/online/sciences/physics/diffrac.html

Scattering: an interaction of light with matter that causes light to change direction amount of scattering depends on wavelength (light with shorter wavelength scatters more) Scattering is what makes the sky blue Blue light has a very short wavelength so it is scattered more than any other color

Real-World Application On page 9 in packet At your station: picture # Type of interaction (reflection, refraction, diffraction, or scattering?) Type of wave (light, sound, water?) 1 piece of evidence…how did you know it was reflection?