1. Not finding help here? Sign up for a free 30min 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!

Power Supplied to a vibrating string

  1. Feb 28, 2013 #1
    1. The problem statement, all variables and given/known data
    I keep getting the wrong answer for this question:

    A taut spring for which μ = 0.05 kg/m is under tension of 80.0N. How much power must be supplied to the string to generate sinusoidal waves at a frequency of 60Hz and an amplitude of 6cm?


    2. Relevant equations
    ω = 2∏f
    v = √(T/μ)
    P = (1/2)μω2A2v

    3. The attempt at a solution
    Convert cm to m --> 6cm = 0.06m

    Find ω
    ω = 2∏(60)
    = 376.99

    Find v
    v = √(80/.05)
    =0.4m/s2

    Find P
    P = (1/2)(0.05)(376.99)2(0.06)2(0.4)
    =5.12

    however, the book tells me the answer is 512W. Did I convert something wrong?

    Watts is J/s, and joules is in (Kg * m2)/s, so it only makes sense that I would have to convert the cm to m.

    By dimensional analysis my answer has the units of :
    (kg * rad2 * m2) / s3
     
    Last edited: Feb 28, 2013
  2. jcsd
  3. Feb 28, 2013 #2

    TSny

    User Avatar
    Homework Helper
    Gold Member

    Check this part of your calculation.
     
  4. Feb 28, 2013 #3
    blah....thanks.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Power Supplied to a vibrating string
  1. Vibrating string (Replies: 3)

  2. String Vibrations (Replies: 1)

Loading...