Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Uhf radio wave - determine frequency

  1. Jul 21, 2010 #1
    1. The problem statement, all variables and given/known data
    in a certain uhf radio wave, the shortest distance between postions at which the elctric an magnetic fields are zero is .34m. determine the frequency of this uhf radio wave


    3. The attempt at a solution

    i basically just divided (3x10^8)/.34 = (8.8x10^8) that is c/d=frequency
    can anyone tell me if that is the correct way to approach the problem? thanks
     
  2. jcsd
  3. Jul 21, 2010 #2

    kuruman

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Re: waves

    How is the "shortest distance between postions at which the elctric an magnetic fields are zero" related to the wavelength?
     
  4. Jul 21, 2010 #3
    Re: waves

    i don't know
     
  5. Jul 22, 2010 #4

    collinsmark

    User Avatar
    Homework Helper
    Gold Member

    Re: waves

    You might want to start by sketching a simple sine wave on a piece of paper. Let y be the vertical axis and t be the horizontal axis.

    y = Asin(2πt)

    Plot the sine wave for a few periods. Make sure to count how many wavelengths you have drawn. Then count how many times the sine wave crosses the t axis. Compare the two.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook