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Find the maximum distance the spring will be compressed?

  1. Sep 24, 2016 #1
    1. The problem statement, all variables and given/known data
    A spring of negligible mass has force constant k = 1800 N/m .

    You place the spring vertically with one end on the floor. You then lay a 1.30-kg book on top of the spring and release the book from rest. Find the maximum distance the spring will be compressed.

    2. Relevant equations
    Potential energy of spring: 0.5kx^2
    Potential engergy by gravity: mgh

    3. The attempt at a solution
    mgx = 0.5kx^2
    mg = 0.5kx
    x=0.01417m(take g=9.81)

    But the answer is 12cm, what's wrong with my approach?
    How can I obtain the correct answer?
    Thank you.
  2. jcsd
  3. Sep 24, 2016 #2


    User Avatar

    Staff: Mentor

    Your approach looks okay to me. Could be a misprint in the text. Sometimes authors change the numbers in problems when they "refresh" a book for new editions and fail to update the answer key accordingly.
  4. Sep 24, 2016 #3
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