This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1-15-08: Chapter 1Sources of lightoStars and sun, not moon (reflection of sun)WavesoRopeoOceanoSoundoShockAmplitudeoChanges wave heightFrequencyoChanges # of waveso1/ TimeoF increases, distance between crests gets shorterDampingoHow long/strong wave lastsWave moves left and rightoRope moves up and downAir carries soundoLight doesnt need air to carry waves (no medium needed)Waves need medium to move (sound)oSound is very slow in speedWaves that do not need medium to move them are electromagnetic waves Periodic wavesoDistance between wavelength Aperiodic wavesoDoesnt repeat itself10 cycles/second Time (t)= 1/10 cycle / second (always the inverse) Period= Time=T= 1/frequencyoMeasuring the time taken for a wavelength to pass a give point, crest to crestLightoVery fast in speedSpeedoDistance/time= wavelength/time= wavelength * frequency1-17-08: Chapter 1C= 3*10^8 m/s and d= 1/3 moCalculateo1/3*(3*10^8)= 10^-9 seconds nanosecondWe cannot see most of the light on the electromagnetic spectrumoVisible light is between 10^-6 & 10^-7oLonger wavelength is infraredoShorter wavelength is *Wavelength of red lighto650 nm= 650 * 10^-9 mo.650 um= .650 * 10^-6 mRadio frequency is 101.5 MHzoAM has longer wavelength that FM radiooWavelength is c/f= cTo(3* 10^8 m/s) / (101.5 * 10^6/s) = 3 meters1-22-08Visible lightoBetween 700 nm (infrared, less energetic, less waves) 400 nm (ultraviolet, more energetic, more waves)Generate a wave on a ropeoRaise and lower one end quicklyLight wavesoDisturbances in the electromagnetic field, a nonmaterial physical entity whose equilibrium state is vacuumElectromagnetic waveoA propagating loopof field linesoCoupled electric and magnetic fieldsoSources of electromagnetic wavesHeatOscillating electric field due to current changesElectrons in an excited atomNeon sign, fluorescent lightChemical excitationFirefly, phosphorescenceAmplitude, wavelength, frequency define direction, energy, and intensity of the radiationGenerating electromagnetic wavesoSourceMechanismRadio stationsvoltage in a circuitMicrowavevoltage in a circuitHuman bodyheat/ neural activityCell phonevoltage in a circuitNeon lightexcited atomsLaserexcited atomsWarm stoveheatResonanceoCauses molecules to vibrate...
View Full Document
This note was uploaded on 11/01/2010 for the course PHYS 1230 taught by Professor Martingoldman during the Spring '07 term at Colorado.
- Spring '07