Waves of the Electromagnetic Spectrum EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Vocabulary Electromagnetic Spectrum Range of electromagnetic waves when they are ordered by increasing frequency Remember all EMW travel at the same speed, but they have different wavelengths and frequencies As the wavelength decreases, the frequency increases The amount of energy carried by EMW increases as its frequency increases. If I have a wave with a large wavelength, will I have a wave with high or low frequency? EQ: What is the electromagnetic spectrum?

Electromagnetic Spectrum EQ: What is the electromagnetic spectrum? Made up of 7 different types of waves What is 10 3? (1000) What is 10-3? (.001) Which wave has more energy – x ray or microwave? Explain how you know the answer using wavelength and frequency.

Radio Waves - EMW with longest wavelengths and lowest frequencies Can travel through a vacuum but most of our radio waves travel through air. 1. Antennas pick up radio waves from the air. 2. Then the radio waves go to the wires in your radio 3. The radio converts the EMW into sound that comes out your radio EQ: What is the electromagnetic spectrum?

Microwaves – shorter wavelengths and higher frequency Microwave ovens and cell phones most common use EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? a transmitter and a receiver cell phones depend on an overlapping network of cells, or areas of land several kilometers in diameter cell tower in the center of “cell” receives and sends microwaves Cell Phones EQ: What is the electromagnetic spectrum?

Radar – shortest wavelength microwaves Stands for radio detection and ranging Used to locate objects Use radio waves and the Doppler effect to calculate speed of vehicles Baseball pitcher, policeman EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Infrared Waves Give off heat – heat lamp, electric stove, toaster. Humans can sense it Have shorter wavelengths and higher frequencies than radio waves Infra means below – below red on the color spectrum Sense but not see EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Infrared Waves Thermogram – pictures taken by infrared camera. Shows regions with different temperatures with different colors Used to detect motion of clouds, growth of plants Developed by the military EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Visible Light EQ: What is the electromagnetic spectrum? The light we can see Longest wavelength of visible light are red, shortest is purple Rainbow or prism refracts, or bends the light waves to produce different colors Smallest section of the spectrum

EQ: What is the electromagnetic spectrum? Visible Light Waves EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Ultraviolet Rays UV rays Ultra is Latin for beyond, so these waves are just beyond the color violet Carry more energy than visible light because they travel at a higher frequency Yellow is what we see, blue is what a bee sees EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Ultraviolet Waves UV lamps used to kill bacteria UV waves help produce vitamin D in the body, cause sunburn Help newborns who have jaundice EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? X - Rays Carry more energy than UV rays because of their higher frequency Can penetrate most matter with the exception of bone and lead. These are too dense Where are the x rays absorbed? (bones) What would a broken thumb look like on this x ray? (black crack on the thumb) EQ: What is the electromagnetic spectrum?

EQ: What is the electromagnetic spectrum? Gamma Rays Shortest wavelength and highest frequency Used in radiation therapy to kill cancer cells Examine body’s internal structure Supernova As the wavelength of an EM Wave decreases, what happens to the frequency? (Increases) What happens to the energy? (Increases) EQ: What is the electromagnetic spectrum?

Class Work and Homework Fill In What did I learn Confused Say Read pages 79– 86 Electromagnetic spectrum jumble questions 1-6 and page 87 “Are cell phones harmful?” EQ: What is the electromagnetic spectrum?