1. What Are Microwaves? Physics 11 Corin Wong

2. IMPORTANT! Microwaves  Microwaves are a type of ELECTROMAGNETIC radiation  In the EM Spectrum, Microwaves fall In the range of the spectrum between radio and infrared light  Microwaves have frequencies ranging from 3 gigahertz up to about 30 trillion hertz  Their Wavelengths range from 3 millimeters to 30 centimeters  Microwaves are a type of ELECTROMAGNETIC radiation  In the EM Spectrum, Microwaves fall In the range of the spectrum between radio and infrared light  Microwaves have frequencies ranging from 3 gigahertz up to about 30 trillion hertz  Their Wavelengths range from 3 millimeters to 30 centimeters

3. The Microwaves In Your Oven KEY: Water Molecules are Dipole Molecules (Dipole meaning opposite charges on either end) IMPORTANT : Microwaves (electromagnetic waves) used for cooking are EM waves which possess frequencies around the 2.4 GHz range EM Waves are waves made up of alternating electric & magnetic fields So what do water molecules have to do with microwave ovens… WATER MOLECULE

4. Build Anticipation Here!

5. How Your Microwave Oven Works o When exposed to an electric field, positively charged molecules are forced in the direction of the field. Negatively charged molecules are forced opposite to the field o Because of this, dipole water molecules will be forced into a constant rotation o Since EM fields are constantly alternating, the rotation direction changes periodically (clockwise & counter-clockwise) o When subjected to vibration, water molecules produce heat energy which then rubs off on nearby molecules such as Food molecules o Remember: If water molecules are well spread out, the subject will heat up faster o When exposed to an electric field, positively charged molecules are forced in the direction of the field. Negatively charged molecules are forced opposite to the field o Because of this, dipole water molecules will be forced into a constant rotation o Since EM fields are constantly alternating, the rotation direction changes periodically (clockwise & counter-clockwise) o When subjected to vibration, water molecules produce heat energy which then rubs off on nearby molecules such as Food molecules o Remember: If water molecules are well spread out, the subject will heat up faster

6. C A U S E Do Microwaves

7. Microwave Ovens DO NOT Cause Cancer! Microwaves do not use X-rays or Gamma rays, they do not make food radioactive They are designed to contain microwaves within the oven itself Microwave leakage is limited to an amount way below what can cause HARM

8. Microwaves & Satellite’s

9. o Microwaves can provide scientists with a variety of information depending on their wavelength o Medium length C-band microwaves penetrate through the atmosphere to reveal earth’s surface o Long L-band microwaves like that used by a GPS can penetrate through the rainforest canopy to measure the moisture of soil o Since microwaves can penetrate through any condition in the atmosphere, scientists use them to penetrate through storm clouds / hurricanes to monitor weather conditions underneath o Devices such as the scatterometer use radar pulses in the ku-band of the microwave spectrum o It measures changes in the energy of the microwave pulses to measure speed and direction of wind near the ocean surface o The PRECISE height of the sea’s surface can also be determined by measuring the amount of time it takes for a sent pulse to return to the satellite Satellite Imaging: Topography & Weather Forecasting

10. Bibliography  Lucas, By Jim. "What Are Microwaves?" LiveScience. TechMedia Network, 26 Mar. 2015. Web. 14 Feb. 2016..  "Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation." Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation. N.p., n.d. Web. 14 Feb. 2016..  Netting, Ruth. "NASA Science." Microwaves. N.p., 13 Aug. 2014. Web. 14 Feb. 2016..  Villanueva, John Carl. "How Do Microwaves Work - Universe Today." Universe Today. Universe Today, 18 Nov. 2009. Web. 14 Feb. 2016..  Lucas, By Jim. "What Are Microwaves?" LiveScience. TechMedia Network, 26 Mar. 2015. Web. 14 Feb. 2016..  "Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation." Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation. N.p., n.d. Web. 14 Feb. 2016..  Netting, Ruth. "NASA Science." Microwaves. N.p., 13 Aug. 2014. Web. 14 Feb. 2016..  Villanueva, John Carl. "How Do Microwaves Work - Universe Today." Universe Today. Universe Today, 18 Nov. 2009. Web. 14 Feb. 2016..