1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Mechanical energy in an harmonic wave and in normal modes

  1. May 20, 2016 #1
    I think I miss something about energy of a mechanical wave.
    In absence of dissipation the mechanical energy transported by an harmonic wave is constant.

    $$E=\frac{1}{2} A^2 \omega^2 m$$

    But, while studying normal modes on a rope, I find that the mechanical energy of a normal mode (still constant) is equal to

    $$E=\frac{1}{4} A^2 \omega^2 m$$

    Is the factor ##\frac{1}{2}## really present and why?
  2. jcsd
  3. May 20, 2016 #2
    Are you sure the first formula is about a wave? What would be the meaning of m?
    Isn't the energy of a harmonic oscillator?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted