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Homework Help: Maximum distance spring compressed.

  1. Nov 10, 2008 #1
    A block of mass m = 1.9 kg is dropped from height h = 77 cm onto a spring of spring constant k = 1510 N/m (Fig. 8-38). Find the maximum distance the spring is compressed.

    My attempt:
    mgh = 1/2kx^2
    (1.9)(9.8)(.77) = (.5)(1510)x^2
    x = 0.138m

    But it's not the correct answer.
    What am I doing wrong?
  2. jcsd
  3. Nov 10, 2008 #2
    gravity is still working on the block when it is compressing the spring

    by writing h in your potential energy, you are saying that h is the distance onlong which the block "feels" gravity

    you are gonna need to add something there...

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