Chapter 11 vocabulary Medium: matter through which a wave travels Wave: disturbance that transmits energy through matter or space Mechanical Wave: wave that requires a medium through which to travel Rarefaction: when coils of a longitudinal wave are stretched out Surface waves: occur at a boundary between 2 different mediums, such as air and water

6. Longitudinal wave: wave that causes particles of the medium to vibrate parallel to the direction the wave travels. Ie sound waves Seismic waves: wave that travels through earth Crest: highest point of a transverse wave Hertz: Si unit for measuring frequency Hz Trough: lowest part of a transverse wave

Speed of light: 3 x 108 m/s or 186,000 mi/s 11. Tsunami: huge ocean wave caused by earthquakes Transverse wave: wave causes the particles of the medium to vibrate perpendicularly to the direction the wave travels-ie light Doppler effect: an observed change in frequency of a wave, when the source of observer is moving Speed of light: 3 x 108 m/s or 186,000 mi/s Wave speed: the speed at which a wave passes through a medium , v=f x λ

16. electromagnetic spectrum: full range of light at different frequencies and wavelengths 17. Period: the time required for one full wavelength to pass a certain point Electromagnetic wave: wave caused by the disturbance in electric and magnetic fields, doesn’t require a medium- also called light wave Wavelength: the distance between 2 successive identical parts of a wave compressions: coils of longitudinal waves that are bunched up

21. Damped harmonic motion: a vibration that fads out as energy is transferred from one object to another wave front: wave spread out evenly and spherically from the source Simple harmonic motion: when motion is continuous forever amplitude: greatest distance that particles in a medium move form their normal position when a wave passes Standing wave: wave form caused by interference that appears not to move along the medium and that shows some regions of no vibrations(nodes) and other regions of maximum vibrations (antinodes)

29. Node: no vibrations in a wave 26. Antinodes: regions of maximum vibrations 27. Frequency: the number of vibrations that occur in a 1 second time interval 28. Pitch: how high or how low a sound is, determined by the frequency at which sound waves strike the eardrum 29. Node: no vibrations in a wave 30. Destructive interference: any interference in which waves combine so that the resulting wave is smaller than the largest of the original waves

31. interference: combination of two or more waves that exist in the same place at the same time reflection: bouncing back of a wave as it meets a surface or boundary Constructive interference: interference in which waves combine so that the resulting wave is bigger than the original waves Refraction: bending of a wave as they pass form 1 medium to another Diffraction: the bending of a waves as it passes an edge or an opening