Characteristics of Waves Section 2 Page

Wave properties Transverse waves have the shape of a sine curve If they have the shape of a sine curve they are called sine waves 98

Know these parts of a transverse wave Crest—highest part of the wave Trough—lowest part of the wave Wavelength—the distance between two crests Amplitude—the height of the wave 98

Amplitude measures the amount of particle vibration The greatest distance that a wave is displaced from its normal resting place Also, half the distance from crest to trough Amplitude is related to loudness!

Wavelength Measures the distance between two equivalent parts of the wave Represented by the Greek letter lambda, λ 100

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Other important terms Period—how long it takes for waves to pass by Symbol is T Symbol is T SI Unit is seconds SI Unit is seconds Frequency –measures the rate of vibrations Symbol is f Symbol is f SI unit the hertz (Hz) SI unit the hertz (Hz) Frequency-Period Equation Frequency = 1/period f=1/T 102

Radio Stations Measure in mHz—millions--FMkHz—thousand—AM 95.1 T-95 classic rock, alternative The FOX classic rock 103

Electromagnetic Spectrum

Radio— AM,FM, TV, radar aircraft navigation Microwave— research and microwave ovens Infrared— infrared photos, remote controls, heat radiation Visible Light— ROYGBIV UV light— sterilizing, fluorescent minerals, (sunburns) X-ray—medical exams, cancer treatment Gamma ray—food irradiation, studies of structural flaws 104

Radio waves have long wave lengths, so low frequency Gamma rays have short wavelengths, so high frequency 104

Visible light is only one small portion of the EM spectrum Red has a long wave length Violet has a short wavelength 105

Speed of Sound 340 m/s Sound travels better in water Sound travels even better in solids 106

Speed of Light Speed of Light 3.00 x 10 8 m/s 186,000 mi/s Depends on the medium 106

Pitch P itch is determined by frequency High pitch = high frequency High pitch = high frequency Low pitch = low frequency Low pitch = low frequency 107

Doppler Effect An observed change in the frequency of the wave when the source or observer is moving 107