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What Are The Basic Physics Principal For GPS, TV and Radio?

  1. Jun 4, 2010 #1
    I'm having to do a project and i got to do a detailed presentation describing and explaining the basic physics principals for gps's, tv's and radio. Each section has to be around 3-4 minutes of explanation.

    Im hitting a big rut with trying to find research for it. Also im in gr.12 physics btw.

    Any help plz.
  2. jcsd
  3. Jun 4, 2010 #2
    When you say TV's, do you mean the old fashion large bulky cathode ray tubes? or the new plasma sort? And you should be able to find plenty of relevant information on wiki
  4. Jun 4, 2010 #3
    both tv's i guess, tubes,plasma,lcd,led,
  5. Jun 4, 2010 #4
    GPS, TV, Radio.

    The common thread is that they all receive and present information to a user.

    What are you trying to "explain" exactly.
  6. Jun 4, 2010 #5
    i just got to talk about the physics principals that each electronic relies on in order to function.
  7. Jun 4, 2010 #6

    Thats a really broad word. It could mean anything from explaining how they receive a signal to explaining what they do with it.

    Maybe you need to narrow down what you are trying to explain. There must be a reason you listed all three things. Either they all have something in common or they all have something unique that you are trying to "explain".
  8. Jun 4, 2010 #7
    Ok, this is quite crude, but I am doing this quickly. Ill be back later to do some of the rest if no one else does first.

    A cathode ray tube is effectively a wire that is heated to produce electrons, which are then accelerated the the positive anode (think thats the right one) which then get deflected by metal plates onto a screen made up of RBG phosphor. That being phosphor that glows Red Blue or Green when sufficiently high energy electrons excite the phosphor to give off photons. The entire wire to phosphor screen is contained within a vacuum.
  9. Jun 4, 2010 #8


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    Staff: Mentor

    You should start by reading how each works at HowStuffWorks.com

    After that, you will be able to ask specific questions about things that you are not understanding...
  10. Jun 5, 2010 #9
    As I read your question, and think of the assignment, I'm looking at what's common. Meaning, they all deal with electromagnetic radiation. The differences are in the frequencies in the electromagnetic spectrum. Radio, Tv, or GPS, they function and provide benefits to us based on carrying information carried on the waves.

    Moving electrons in a medium creates an electromagnetic field. Varying that current will vary the field. Modulating and controlling the current in a meaningful way makes it information.

    I would start with the basic principle that each share, the electromagnetic spectrum, and the harnessing of the energy.

    Radio, Tv, and GPS function with different frequency ranges, each having a particular behavior. Certain frequencies travel through some mediums and are effected by it. Others not. AM and FM frequencies behave differently, while microwaves drill past barriers that stop radio and tv cold. Some frequencies stay local (get absorbed and dissipate into the medium) while others literally bounce like a ball and carry on by virtue of reflection. Others still just penetrate and blow on by.

    If you think about listening to AM versus FM, how far those signals go, why, and why you might like to use a highly energetic signal to carry location data reliably in straight lines (think of your trig classes), I believe you already have enough information to begin a pretty informative and well though out presentation. Good Luck.
  11. Jun 5, 2010 #10
    And maybe talk about how the gps satellites have to take into account time dilation from relativity because they are in a weaker gravitational field and because they are going so fast .
  12. Jun 5, 2010 #11
    Wow! Cragar....most excellent point. In terms of this assignment, to bring that up, and it's relevance, truly makes the point that physics, the sciences, are not just book study classroom ideas.

    This is real, and it's all around us right now. AND, it's the A-maker idea. Nice.
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