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calculating frequency! watch

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    im stuck on this question:

    a microwave generator produces plan polarised electromagnetic waves of wavelength 29mm.
    calculate the frequency of this radiation.

    i know the answer is 1.30x10^10Hz

    i just dont know how you work it out? help!
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    Wavelength = speed of light / frequency
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    speed = frequency x wavelength
    its EM radiation so you know the speed just rearrange to work it out
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    (Original post by Jack_wills)
    im stuck on this question:

    a microwave generator produces plan polarised electromagnetic waves of wavelength 29mm.
    calculate the frequency of this radiation.

    i know the answer is 1.30x10^10Hz

    i just dont know how you work it out? help!
    aww.its okay here is some help.

    The speed of all ELECTROMAGNETIC waves is 3.00X10^8
    Convert 29mm to meters =0.029m.

    Then you divide. 3.00X10^8 / 0.029..

    Answer should be 1.03 not 1.30..

    get it?
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    (Original post by Jack_wills)
    im stuck on this question:

    a microwave generator produces plan polarised electromagnetic waves of wavelength 29mm.
    calculate the frequency of this radiation.

    i know the answer is 1.30x10^10Hz

    i just dont know how you work it out? help!
    OK.

    The generator generates microwaves, which are electromagnetic waves. You know that electromagnetic waves travel at 3x10^8m/s (in a vacuum). You also know that the wavelength is 29mm.

    You can use the equation:

    wave speed = frequency x wavelength

    Rearrange it to get:

    frequency = wave speed / wavelength

    You already have the wave speed and the wavelength, so just use the above equation to work out frequency, remembering that the wavelength needs to be in metres before putting it into the equation.

    EDIT: Lol, beaten to it!
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    Just as an additional note:

     v = f\lambda

    Where

    v = velocity,
    f = frequency
    \lambda = Wavelength.

    But, EM radiation moves at the speed of light, which means:

     c = f\lambda

    Where c = the speed of light.
    And the speed of light is a constant value,

     c \approx 3\times10^8

    That should help.

    _Kar.
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    thanks for all the help! thats much clearer now! and yes sorry that was a typo 1.03!
 
 
 
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