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Homework Help: Spring Frequency

  1. Mar 16, 2008 #1
    1. The problem statement, all variables and given/known data
    A mass of .88 kg when fastened to the lower end of a light-weight spring and set vibrating up and down is found to have a frequency of 1.8 Hz. Calculate the new frequency of vibration when the mass is decreased to .4 kg.

    2. Relevant equations
    P = 2 [tex]\pi[/tex] [tex]\sqrt{m/k}[/tex]

    3. The attempt at a solution
    Using K = (m 4 [tex]\pi[/tex]^2 ) / P^2, my answer for K comes out to 112.56.

    But, using [tex]\sqrt{k}[/tex] = ([tex]\sqrt{m}[/tex] 2 [tex]\pi[/tex] )/ P, I get 3.2572. But how can that be? The equations are the same, aren't they? Where am I making the mistake?

    Thanks.
     
  2. jcsd
  3. Mar 17, 2008 #2
    [tex]2\pi f=\sqrt{\frac{k}{m}}[/tex]
     
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