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!

Tension in guitar string

  1. Jan 2, 2010 #1
    A guitar string 60 cm in length, with a diameter of 1.4 mm and a tension of 289 N, emits a note with a frequence of 147 Hz. Find the frequency in each of the followig situations:

    a)the tension isreduced to 196N
    b)a string of the same material, 45 cm long and 1mm in diameter under 168 N of tension, is plucked.

    I have no idea for a, but I was hoping someone could check my work on b?
    =Fi(square root of tension fraction)(length fraction)(diameter fraction)
    =147Hz(square root of 169/289)(60/45)(1.4/1)
    =209.8Hz

    I am just getting confused as to if the 289 goes on top of the fraction, or the 169.

    thanks for your help in advance!
     
  2. jcsd
  3. Jan 2, 2010 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    It would help if you put units in the equations then you can easily check that you have them the correct way around.

    frequency = sqrt ( Tension / mass per unit length )
    s-1 = sqrt ( N / Kg m -1 )
    s-1 = sqrt ( kg m s-2 / Kg m -1 ) = sqrt(s-2)
     
  4. Jan 2, 2010 #3
    thankyou. Can you please help me with part a as well?
     
  5. Jan 2, 2010 #4

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    The frequency is proprtional to sqrt(tension)
     
  6. Jan 2, 2010 #5
    thanks again
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook