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Spring with Work and Energy

  1. Nov 17, 2011 #1
    1. The problem statement, all variables and given/known data
    A block with mass m = 4.00 kg is attached to a spring with spring constant k = 500 N/m, and it slides on a horizontal table that is not frictionless. At a time when the spring is compressed by 3.00 cm, the block is observed to be moving toward the right (decompressing the spring) at 0.600 m/s. When the block reaches the point where the spring is completely relaxed, the block is measured to be moving at 0.550 m/s. (a) What is the net work done on the block during the time interval? (b) What is the work done by the spring? (c) What is the work done by friction? (d) What is the coefficient of kinetic friction between the block and the table?

    2. Relevant equations

    3. The attempt at a solution
    I honestly am lost, i know how to do a, but not anything after
  2. jcsd
  3. Nov 18, 2011 #2
    The net work done by the spring is given by the change in the spring's potential energy between two positions (the compressed one and the relaxed one), spring potential is
    [tex] PE = \frac{1}{2}kx^2 [/tex]
    Where x is the displacement from the relaxed position.
    Since you know the total work and the part of the work done by the spring parts (c) and (d) follow :)
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