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!

Homework Help: Help with displacement and velocity of waves on a string (using trig)

  1. May 11, 2010 #1
    Hello all,

    excited to be on the forums. I'm having trouble solving a problem from one of my past exams (prepping for final). Could you please guide me?

    The displacement associated with a wave on a string has the functional form y = 0.2 cos (10x - 4t). What is the wave speed?

    The answer is 0.4 m/s...but how do I get here? what is really bothering me is the "10x"...I'm used to the format y = Acos(wt), where wA = v.


  2. jcsd
  3. May 11, 2010 #2
    Use the wave equation since it is a wave.
  4. May 11, 2010 #3
    yeah...but what do I do with the "10x"?
  5. May 11, 2010 #4
    There is no 10x you are using the differential wave equation right?
    \frac{\partial^2\psi}{\partial x^2} = \frac{1}{v^2}\frac{\partial^2\psi}{\partial t^2}
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook