Agenda 1st 20 minutes – Wave Behavior Poster You will be given a type of wave behavior. Write the behavior in Big Letters on the top of your page. Put the definition and importance Draw a picture. 30 minutes – Electromagnetic Spectrum Notes

QW 1/16 On your waves cheat sheet, fill in the wave diagram for: Amplitude (2 times), Crest (2 times), Trough (2 times), Wavelength (2 times) Write your definition of frequency and wavelength. Look at the electromagnetic spectrum diagram. Which type of waves do you think have the highest frequency based on what you see?

Share with your neighbor Share definitions of wavelength and frequency Share observations of the electromagnetic spectrum

Take notes on the back of the cheatsheet!

The Physics of Light

Early Concepts of Light The Greek philosopher Socrates thought that vision resulted from streamers emitted from the eyes.

Christian Huygens Wave Model of Light Christian Huygens (1596 - 1687), a Dutch mathematician and scientist, proposed a wave theory of light. The wave theory of light states that light travels in waves in all directions from its light source.

Isaac Newton's Theory of Color Isaac Newton 1643 -1727, an English mathematician and scientist proposed that sunlight is a blend of all the colors of the rainbow. He demonstrated his theory by passing light through a prism of glass, which separated it into separate colors.

Y Electric Field Z x Magnetic Field Electromagnetic Waves James Clerk Maxwell 1831–1879, a Scottish scientist, showed that light is a wave that is partly electric and partly magnetic. Such a wave is called an electromagnetic wave. x Y Z Electric Field Magnetic Field

Wavelength The distance from crest to crest is the wavelength Wavelength The distance from crest to crest is the wavelength. Each type of electromagnetic radiation has its own characteristic wavelength.

Frequency The frequency of a wave is the number of waves that pass a given point per second. Each type of electromagnetic radiation has its own characteristic frequency.

Frequency and Wavelength If light was a train, the wavelength would be the length of one car and the frequency would be the number of cars that pass each second. The frequency of train cars is the number of cars that pass per second.

How the Atmosphere Protects Electromagnetic Spectrum Light, radio, infrared, and ultraviolet are forms of energy that travel in waves called electromagnetic energy. Together these forms of energy form the electromagnetic spectrum.

Energy of Electromagnetic Radiation The electromagnetic waves are organized in order of wavelength. The shorter the wavelength, the higher the frequency and energy of the electromagnetic wave. An X ray has roughly a trillion times the energy of a radio wave. A photon (light particle) of gamma radiation has an energy of 1 million electron volts, while a photon (radio particle) of radio has the energy of only 1 millionth electron volt.

Speed of waves All waves in the spectrum move at a constant speed of 3 * 10^8 m/s (300000000 m/s) in a vacuum.

Radio waves have wavelengths that range from 1 to thousands of meters, while light has wavelengths of billionths of a meter.

Radio waves have frequencies of thousands of waves per second while light has frequencies of billions of waves per second.

Radio Waves Used for communication Sent out at varying amplitudes and frequencies (AM and FM)Radios AM: Amplitude Modulation (540 – 1620 KHz) FM: Frequency Modulation (87 -108 MHz) Walkie-Talkies Television Signals

AM 850 For example, Denver’s Radio KOA 850 broadcasts at 850,000 waves per second. Its wavelength is 353 meters.

Microwaves Microwaves Used in communication Microwave Oven Cell Phones Satellite Dishes Microwave Oven Cause fat and water molecules to move faster and get warmer

Infrared Infra means “below” Heat Remote controls for electronics Security Devices Night photography

Infrared Radiation

Journal 1/17 How does the wavelength of Infrared Waves compare to Radio Waves? How does the frequency of x-rays compare to infrared waves?

Article #1 1. How are we dependent on wireless devices? 2. How does the electromagnetic spectrum affect our lives? 3. How is the military reliant on the electromagnetic spectrum? 4. How can utilizing waves in the electromagnetic spectrum be a challenge?

ELECTROMAGNETIC SPECTRUM The Visible Spectrum The visible spectrum consists of wavelengths that are visible to the human eye. These are the colors of the rainbow, red through violet. ELECTROMAGNETIC SPECTRUM R O Y G B I V

For example, red light has a frequency of 625 trillion waves per second and a wavelength of 650 billionth of a meter.

Red light consists of longer wavelengths and lower frequencies than violet light. Violet light consists of shorter wavelengths and higher frequencies than Red light.

Colors: ROYGBV 380-440 nm — wavelength of violet light 440-520 nm — wavelength of blue light 520-565 nm — wavelength of green light 565-590 nm — wavelength of yellow light 590-625 nm — wavelength of orange light 625-740 nm — wavelength of red light

Ultra Violet Used by body to produce Vitamin D Can kill living cells Over exposure = Skin cancer Tanning Salons Sun Burns Special UV lamps

X-Rays High Energy waves that pass through most substances Used to take pictures of objects that absorb radiation photons

Gamma Rays Extremely high frequency waves and high energy. Difficult to control – Concrete or lead Used to treat some types of cancer

Comparison Matrix In your notebooks, create this comparison matrix and fill it out using your notes. Radio Waves Micro Infrared Visible Light Ultra Violet X-Rays Gamma Rays Similarities/Differences Frequency Wavelength Uses/real life examples

Summary Write a summary beneath your matrix describing the organization of the electromagnetic spectrum.

Article #2 Underline important facts relating to greenhouse gases List positives and negatives to rising temperatures.

Using your TRIANGLE Write out what you know! Look at your triangle! Write out your equation! Do the Math! If the velocity is not given, assume it is the Speed of Light C = 300,000,000 meters/second C = 3x10 8 meters/second

Write down what you know A sound wave travelling in air has a wavelength of .16 m. If the velocity of sound is 320 m/s, calculate the frequency of sound. Write down what you know Wavelength = .16 meters Velocity = 320 meters/sec Look at your triangle Write out your equation Do the math

IMPORTANT!! BRING A CALCULATOR TOMORROW!!!