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Homework Help: Stupid question sorry

  1. Feb 1, 2005 #1
    This sounds like a stupid question. However my teacher didnt really explain it well.
    Its my first day back at school, cut me some slack thx.

    - Calculate the frequency of a lightwave of wavelengh 500nm. Travelling at speed of light (3x10^8 ms-1)
    -----------------------------------------
    I WILL SUBSITUTE LAMBDA for H (cause i dont know how to type it)

    f = ?
    h = 500nm
    V = 3x10^8 ms-1.

    So 500nm x 10^-9 = 0.0000005m

    V = fh

    Therefore f = h/V

    0.0000005m / 3000 000 00ms = ???

    Would that be 1.66666666666666666 x10^-15???

    BTW- can someone tell me how to input equations?
     
  2. jcsd
  3. Feb 1, 2005 #2
    your algebra is not quite correct
     
  4. Feb 1, 2005 #3
    err,
    V = fXh
    Divide out the f... f/V = h. So you would have to multiply out the V to get/

    f = vh ??

    0.0000005m x 3000 000 00ms = ???

    so F=150? ?
     
  5. Feb 1, 2005 #4
    V = fh

    V/h = fh/h
    V/h = f

    from memory green light should have a freq around something x 10^14
     
  6. Feb 1, 2005 #5
    6 x 10^14 perhaps?

    How could i cock it up that much? TWICE! But I see the logic now.
    Thankyou.
     
  7. Feb 1, 2005 #6
    [tex] f = \frac{v}{\lambda} [/tex] where [tex] v [/tex] is speed and [tex] \lambda [/tex] is wavelength.
     
  8. Feb 1, 2005 #7

    DaveC426913

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    Gold Member

    Read the sticky post on LaTEX typesetting.
     
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