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Homework Help: Conservation of energy involving spring and friction

  1. Oct 25, 2008 #1
    1. The problem statement, all variables and given/known data

    A 0.62 kg wood block is firmly attached to a very light horizontal spring (k = 180 N/m) . This block-spring system, when compressed .05 m and released, stretches out 0.023 m beyond the equilibrium position before stopping and turning back.

    What is the coefficient of kinetic friction between the block and the table?


    3. The attempt at a solution

    This is how far I've gotten:

    At x = -.05, there is 0 kinetic energy, and potential energy = 1/2 kx2.


    1/2 kx2 = 1/2 mv22 + [tex]\mu[/tex]mg(energy lost due to friction)

    But this has 2 unknown variables.

    Any help is greatly appreciated.
  2. jcsd
  3. Oct 25, 2008 #2
    Nevermind, figured it out.

    1/2 kxinitial2 = 1/2 kx2final + [tex]\mu[/tex]mg(abs((xfinal - xinitial))
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