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: Finding driving frequency.

  1. Mar 18, 2010 #1
    1. The problem statement, all variables and given/known data

    A harmonic oscillator is driven at its natural frequency by an outside force. If the spring constant is 187.5 N/m and the oscillator's mass is 26.1 kg, what is the driving frequency? The damping constant is 15.2 kg/s.

    2. Relevant equations

    w=omega=driving frequency
    m(d^2x/dt^2)= -kx -b(dx/dt) + Fcos(wt)


    A= F/(m((wd^2-wo^2)^2 + (b^2)(wd^2/m^2))^.5

    3. The attempt at a solution
    We are given three of the necessary factors for the first equation but not x so i'm not sure if I can use it. I considered using the formula for Amplitude so that A=v/w. I also know that w=(k/m)^.5. However don't have force.
    I don't have a great understanding of driven oscillations, (my book has all of 2 paragraphs on it) so any information is helpful. thanks
  2. jcsd
  3. Mar 18, 2010 #2
    Unless you have a follow up question you don't need to know the damping constant. The natural frequency is defined as sqrt(k/m). Easy as that.
  4. Mar 18, 2010 #3
    Omy god. Thanks so much, I guess i got wrapped up in using the formula to calculate something.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook