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.