Energy may ______________________________as a wave travels. Waves WAVE: ______________________________ disturbance that transfers ______________________________ through space, matter, and time. Energy may ______________________________as a wave travels. When sound waves travel in air, the waves spread out in spheres. As they travel outward, the spherical wave fronts get bigger, so the energy in the waves spreads out over a larger area.

Waves 2 Main Types of Waves ______________________________________________: require a medium. Matter through which a wave travels is called the ____________________ (air, water, earth, rope, metal, etc) ____________________________________________: do not require a medium (can travel in a vacuum). Light waves consist of changing electric and magnetic fields in space. Travel at the speed of light (~300,000,000 m/s in a vacuum) Sound wave compressing air molecules

2 Ways Waves are Shaped/Transport Energy ______________________________________________: wave in which the particles of the medium vibrate _______________________ to the direction of wave motion. Sound waves and seismic P- waves are longitudinal. ________________________________________________: wave in which the particles of the medium move ________________________ to the direction the wave is traveling. Light waves and seismic S-waves are transverse.

Parts of a Transverse Wave Waves An ideal transverse wave has the shape of a sine curve _______________________ = highest point of a transverse wave. _______________________ = lowest point of a transverse wave. _______________________ = maximum distance that the particles of a wave’s medium vibrate from their rest position. The energy of a mechanical wave is related to the amplitude. _____________________ () = distance from any point on a wave to an identical point on the next wave.

Frequency – Wavelength Relationship Waves FREQUENCY: _____________________ of complete waves (or cycles) per unit of time (usually seconds). The symbol for frequency is f. The SI unit for measuring frequency is ______________________ (Hz). Frequency – Wavelength Relationship ________________________ wavelength = ________________________ frequency = more energy ________________________ wavelength = ________________________ frequency = less energy Wavelength = _______ Frequency = ________ 3 cm 1 second Wavelength = _______ Frequency = ________ 3 cm 1 second

Speed of a mechanical wave depends on the _______________. Waves MECHANICAL WAVE SPEED Speed of a mechanical wave depends on the _______________. Mechanical waves generally travel: ____________________ in solids ____________________ in liquids ____________________ in gases ELECTROMAGNETIC WAVE SPEED All electromagnetic waves in empty space (a vacuum) travel at the speed of light, which is 300,000,000 m/s (186,000 mi/s). EM waves travel __________________________ in a medium

Wavelength = _________ Amplitude = ___________ Frequency = __________ Waves 2.5 cm Wavelength = _________ Amplitude = ___________ Frequency = __________ 4 cm 5 cm 8 cm Wavelength = _________ Amplitude = ___________ Frequency = __________ 10 cm Wavelength = _________ Amplitude = ___________ Frequency = __________ 2 cm 1 Second

Four Defining Properties of Waves plus Polarization and Doppler Effect

Waves #1 REFLECTION: The __________________________________________________of a ray of light, sound, or heat when the ray hits a surface that it does not go through (echo, mirror image, etc.). #2 DIFFRACTION: The bending of waves ___________________________________________________.

Waves # 3 REFRACTION: Bending of waves when ______________________________________________________at an angle Caused by a change in speed of the wave White light __________________________ into the separate colors __________________________ in a prism or raindrop

Waves Waves in the same place combine to produce a single wave… #4 INTERFERENCE: ____________________________ of two or more waves of the same frequency that results in a single wave. Resulting wave can be found by _________________________________of the waves at each point. Crests are considered _______________________, and troughs are considered ________________________. Principle of : When 2 waves interfere, the resulting wave is a combination of the first 2 waves

Waves ___________________________________ INTERFERENCE: waves combine so that the resulting wave is bigger than the original waves; the amplitude __________________________. ___________________________________ INTERFERENCE: waves combine so that the resulting wave is smaller than the largest of the original waves; the amplitude __________________________. Waves can cancel each other out (sound canceling headphones)

Applications of Wave Properties Waves Color on Soap Bubbles Result of _____________________ and ________________________ Rainbows _________________________________________________________ Fiber optics Use _____________________________________________________ TIR = complete reflection that takes place within a substance when the angle of incidence of light striking the surface boundary is less than the critical angle. TIR and Fiber Optics Rainbows Bubbles

Blue Sky & Red Sunsets ______________________________________ scatter light rays. ______________________________________ (blue, violet) are scattered more easily. ________________ less atmosphere less scattering blue sky, yellow sun _____________________ more atmosphere more scattering orange-red sky & sun

Polarization (Property of Light Waves) Causing light waves to be oriented in a _________________ Waves

changes when the source of waves is moving. The of a sound (how high or low) is determined by the at which sound waves strike the eardrum in your ear. Higher-pitched sound is caused by sound waves of higher frequency and vice-versa. changes when the source of waves is moving. Doppler effect = observed change in the frequency of a wave when the source or observer is moving. Shorter wavelengths/high frequency in of the moving source Longer wavelengths/low frequency the moving source