Presentation on theme: "Table of Contents The Nature of Electromagnetic Waves"— Presentation transcript:
1Table of Contents The Nature of Electromagnetic Waves Waves of the Electromagnetic SpectrumProducing Visible LightWireless Communication
2Electromagnetic Waves The Nature of Electromagnetic WavesElectromagnetic WavesBelieve it or not, you are being “showered” all the time, not by rain but by waves.
3What Is an Electromagnetic Wave? The Nature of Electromagnetic WavesWhat Is an Electromagnetic Wave?An electromagnetic wave consists of vibrating electric and magnetic fields that move through space at the speed of light.
4Models of Electromagnetic Waves The Nature of Electromagnetic WavesModels of Electromagnetic WavesMany properties of electromagnetic waves can be explained by a wave model. Only some light waves pass through a polarizing filter. The light that passes through vibrates in only one direction and is called polarized light.
5Outlining The Nature of Electromagnetic Waves An outline shows the relationship between main ideas and supporting ideas. As you read, make an outline about electromagnetic waves. Use the red headings for the main ideas and the blue headings for the supporting ideas.The Nature of Electromagnetic WavesWhat Is an Electromagnetic Wave?Producing Electromagnetic WavesEnergySpeedModels of Electromagnetic WavesWave Model of LightParticle Model of Light
6Links on the Nature of Waves The Nature of Electromagnetic WavesLinks on the Nature of WavesClick the SciLinks button for links on the nature of waves.
7End of Section: The Nature of Electromagnetic Waves
8What Is the Electromagnetic Spectrum? Waves of the Electromagnetic SpectrumWhat Is the Electromagnetic Spectrum?The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.
9Scientific Notation Waves of the Electromagnetic Spectrum Frequencies of waves often are written in scientific notation. A number in scientific notation consists of a number between 1 and 10 that is multiplied by a power of 10. To write 150,000 Hz in scientific notation, move the decimal point left to make a number between 1 and 10:In this case, the number is 1.5. The power of 10 is the number of spaces you moved the decimal point. In this case, it moved 5 places:150,000 Hz = 1.5 X 105 Hz
10Scientific Notation Waves of the Electromagnetic Spectrum Practice ProblemA radio wave has a frequency of 5,000,000 Hz. Write this number in scientific notation.5.0 X 106 Hz
11Electromagnetic Waves Waves of the Electromagnetic SpectrumElectromagnetic WavesElectromagnetic waves are all around you–in your home, your neighborhood, and your town.
12The Electromagnetic Spectrum Waves of the Electromagnetic SpectrumPreviewing VisualsBefore you read, preview Figure 3. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.The Electromagnetic SpectrumQ. Which electromagnetic waves have the shortest wavelength?A. Gamma rays have the shortest wavelength.Q. Which electromagnetic waves have the lowest frequency?A. Radio waves have the lowest frequency.
13End of Section: Waves of the Electromagnetic Spectrum
14Incandescent Lights Producing Visible Light An incandescent light is a light bulb that glows when a filament inside it gets white hot.
15Neon Lights Producing Visible Light A neon light is a sealed glass tube that contains neon gas.
16Comparing and Contrasting ProducingVisible LightComparing and ContrastingAs you read, compare and contrast the five types of light bulbs by completing a table like the one below.Ordinary Light BulbTungsten-HalogenFeatureFluorescentVaporNeonBulb MaterialGlassQuartzGlassGlassGlassHot/CoolHotVery HotCoolCoolCoolHoles in data from book.Tungsten filament and nitrogen gas and argon gas insideHas tungsten filament and a halogen gas insideHas neon or argon gas and solid sodium or mercury insideMakeupA gas and a powder coating insideHas neon gas insideMore efficient than ordinary bulbEfficiencyNot efficientVery efficientVery efficientVery efficient
17Data Sharing Lab Producing Visible Light Click the PHSchool.com button for an activity about sharing data for the Consumer Lab Comparing Light Bulbs.
19Radio and Television Wireless Communication In AM transmissions, the amplitude of a radio wave is changed. In FM transmissions, the frequency is changed.
20Comparing Frequencies WirelessCommunicationComparing FrequenciesThe table shows the ranges of radio broadcast frequencies used for AM radio, UHF television, FM radio, and VHF television.
21Comparing Frequencies WirelessCommunicationComparing FrequenciesInterpreting Data:In the table, what units of measurement are used for frequency?Kilohertz (kHz) and megahertz (MHz)
22Comparing Frequencies WirelessCommunicationComparing FrequenciesInterpreting Data:Which type of broadcast shown in the table uses the highest frequency radio waves? Which uses the lowest frequency waves?UHF television uses the highest frequency radio waves, and AM radio broadcast uses the lowest frequency radio waves.
23Comparing Frequencies WirelessCommunicationComparing FrequenciesCalculating:Which type of broadcast uses waves with the shortest wavelength?UHF television uses waves with the highest frequency and therefore the shortest wavelength.
24Comparing Frequencies WirelessCommunicationComparing FrequenciesInferring:A broadcast uses a frequency of 100 MHz. Can you tell from this data if it is a television or radio program? Explain.You cannot tell from this data if it is a television or radio program, because VHF television and FM radio both broadcast radio waves with a frequency of 100 MHz.
25Cellular Phone System Wireless Communication In the cellular phone system, cellular phones transmit and receive radio waves that travel to the nearest tower.
26Communication Satellites WirelessCommunicationCommunication SatellitesIn the Global Positioning System (GPS), signals from four satellites are used to pinpoint a location on Earth.
27Using Prior Knowledge Wireless Communication Your prior knowledge is what you know before you read about a topic. Before you read, write what you know about wireless communication in a graphic organizer like the one below. As you read, continue to write what you learn.What You KnowCellular phones don’t use wires.Radio and television signals travel through the air.What You LearnedThe signals for radio and television programs are carried by radio waves.The signals can be transmitted by changing either the amplitude or the frequency of the radio waves.Cellular phones transmit and receive signals using microwaves.
28Links on Using Waves to Communicate WirelessCommunicationLinks on Using Waves to CommunicateClick the SciLinks button for links on using waves to communicate.