WIRELESS COMMUNICATION & EM WAVES
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WIRELESS COMMUNICATION & EM WAVES
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| Subject
Area |
Electromagnetic Waves & Communication Protocols |
| Age
or Grade |
Ninth Grade Physics Class (Ages 14-15) |
| Estimated
Length |
Four full class periods, spanning two weeks. |
| Prerequisite
knowledge/skills |
The four wave properties. Understanding of metric definitions (i.e. bits per second) |
| Description
of New Content |
The electromagnetic spectrum and understanding the different types of EM waves is an important lesson in this project. Also, the equation, speed of a wave = wavelength * frequency is reinforced. By applying this equation to all types of EM waves, all velocities were found to be the speed of light. Another main area was learning about communication protocols, and wireless security. |
| Goals |
To be able to identify the position of any EM wave in the spectrum. To be able to find any one unknown between velocity, frequency, and wavelength. Obtain a better understanding of communication protocols. Students were asked to form groups and try to send the most amount of characters from a message in the shortest amount of time. This all had to be done without any other group deciphering what was being sent. |
| Materials
Needed |
Wireless communication devices to be modified by students. This included: Remote control car. Walkie talkies. Light bulbs. Remote controls. Camcorders to detect IR. Laser Pointers. |
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Procedure
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Opener The week before project was initiated students were given takehome questions to get them thinking about what could be around them that they might not be able to see. For example, "What is something our five senses can detect, but we cannot see?", "How could you explain color to a person born blind?", and "What is something that is around us right now, that our five senses cannot detect?" Development Throughout the project demonstrations were performed for students to see the ties between what they were doing and real life exmaples. This included the history of communication from smoke signals to high speed wireless communication. Along with everday examples of EM waves that the children are familar with and have experienced, but can now tie together with Physics. Closure Final discussions on how their project results (highest throughput) compared with that of modern communication. The highest speed a group was able to obtain was 12.5 bits per second. Today's wireless communication can transmit 7 million bits per second!
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| Evaluation |
Each group of 4-5 students competed against each other to make a wireless system that had the highest effective throughput. |
| Extensions |
Extensions were made into sound waves and the tie between electricity and magnetism, and even slightly into Maxwell's equations. |
| References | http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html |