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: A question about string tension

  1. Aug 1, 2011 #1
    1. The problem statement, all variables and given/known data

    The A string on a violin has a fundamental frequency of 440Hz.
    The length of the vibrating portion is 31.2cm and has a mass of
    0.355g. Under what tension must the string be placed? (Find the
    answer in the usual metric unit of tension, the Newton, but do not enter

    2. Relevant equations

    square root of Tension/(mass/length) = velocity of string.

    Velocity = frequency X wavelength

    3. The attempt at a solution

    Soo.... V = square root OF Tension/ (.355g/.321 m) (or do I need to convert grams to kilograms?)

    So to find velocity i was thinking V = frequency X wavelength. So... (440Hz X .642) which is 282.48..

    So velocity = 282.48? then that would mean that 282.48 = squareroot of Tension/ (.355g/.321 m) ?

    Am I on the right track?
  2. jcsd
  3. Aug 1, 2011 #2
    Always keep an eye on units. Since you need tension in Newtons, you mass always needs to be in kilograms (1 Newton is equal to 1 kg.m.s-2)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook