Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
The Electromagnetic Spectrum
Transcript of The Electromagnetic Spectrum
Electromagnetic Spectrum What is the Electromagnetic Spectrum? Radio Waves - They have the longest wavelengths (about 30cm and over), but the lowest frequencies.
- Radio stations use modulation, changing the waves' wavelength or frequency, in order to encode information.
- Television also uses radio waves to broadcast, and use both AM and FM signals. AM and FM waves: • AM waves are waves that have had their amplitude changed, or "amplitude modulation"
- AM waves travel further, because they can bounce off of the atmosphere.
• FM waves are waves that have had their frequency changed, or "frequency modulation"
- FM waves have better sound quality than AM waves, because they are less affected by electrical noise. - Radio Detection and ranging (Radar)
• They use microwaves in order to calculate the speed and location of objects.
- They are used by:
• police officers to calculate the speed of cars
• helping ships navigate at night
• watch the movement of airplanes Infrared Waves - Microwaves have shorter wavelengths and higher frequencies than radio waves.
- Microwaves are used to cook food, send information, and send signals to cell phones. - They have shorter wavelengths and higher frequencies than microwaves.
- Almost every object gives off infrared waves, including you, and the sun, and due to the temperature of an object.
- The warmer the objects is, the more infrared waves the object creates than cool objects
- Infrared waves are not visible for human, but some devices can detect infrared waves. Visible Light - Visible light is the very narrow range of wavelengths and frequencies in the electromagnetic spectrum that is visible for human.
- Visible light from the sun is called the White Light, White Light is visible light of all wavelengths combined. Colors Ultraviolet Light - Ultraviolet light is used to kill bacteria and helping cells produce Vitamin D Bad Effects: X-Rays and Gamma Rays Good Effects: X-Rays -The wavelengths of x- rays are between 0.001 nm and 60 nm, so that can pass through many materials.
- Since it can go through lots of materials it is used in hospitals to take pictures of bones. However, too much eposrue to it can harm you by killing or damaging living cells
-Parts where x-ray exposure is unnescesary is protected by aprons. These aprons are lined with lead because X rays cannot pass through lead. X rays & gamma rays possesses the shortest wavelengths and highest frequencies of all EM waves. Gamma Rays - Gamma rays are one of EM waves that consists of wavelengths shorter than 0.1 nm, making those rays possible to panatrate most materials very easily.
-Doctors uses this rays lots of times to kill cancer cells, but it can have bad side effects since some healthy cells could get killed together.
-Since gamma rays kills bacterias but dosent harm or stays in food making it safe to eat foods cleansed by gamma rays. - The electromagnetic spectrum is the entire range of electromagnetic waves.
- The waves are divided into groups, according to their wave speed.
- The three most common types of electromagnetic waves are radio waves, microwaves, and infrared waves. What is Electromagnetic Spectrum? Microwaves - Too much ultraviolet light causes sun burns.
-Too much ultraviolet light can also cause skin cancer, wrinkles, and damage to the eyes.
-Even though most of the ultraviolet light dosen't reach our surface, it is necessary for people to protect them from ultraviolet light.
- In order to protect you body from ultraviolet light you have to use sunblock creams with high SPF(sun protection factor), wear sunglasses for eye protection and cover much bare skin as possible.
-Even during overcast days you need to protect your skin because UV light can travel through clouds. - Humans can verify which color an object is through the wavelengths of visible lights. The shortest wavelengths are purple, and the longest are red.
- The range of colors is called the "visible spectrum"
- You can use "Roy G. Biv" in order to remember the colors of each visible light. ROY G. BIV stands for: red, orange, yellow, green, blue, Indigo, and violet. Thank You For Watching Game Time!! 1. Divide the cards into two groups: Questions and Answers 2. Mix each group of cards around seperately 3. Match the cards