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: Frequency of a wave?

  1. Nov 16, 2006 #1
    i have a question about the frequency of a wave. I thought it was measured in Hz but sometimes in the textbook it said it's measured in
    s-1 (-1 in superscript lol)
    are they both the same thing?
    but in one of the questions it asked to calculate the wavelength in the substance if the frequency is 1000s-1 and the speed of sound in the medium is 1230m/s
    If 1000s-1 is the same thing as 1000Hz, why do i get a wrong answer?
    I had to use 1000-1 (which is 0.001) to calculate this problem
    So what's the difference between the two??? :confused:
  2. jcsd
  3. Nov 16, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    A hertz is a fancy name for 'cycles per second' and has the unit of [tex]s^{-1}[/tex]. So [tex]f = 1000Hz = 1000 cycles/sec = 1000s^{-1}[/tex]. In your wavelength problem, you may have transposed the formula. wavelength [tex]\lamda = v/f =1230/1000 = .001(1230) = 1.2m[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook