1. The problem statement, all variables and given/known data Problem: Given the mass spring system solve for k1 The natural frequency wn = 10 s-1 k1=2k2 m=1kg 2. Relevant equations wn=(k/m).5 3. The attempt at a solution solve for k1 m x w2n =2.5k1 k1 = 40 N/m Note: I calculate 40 N/m and the solution states 250 N/m. I think I am having a fundamental misunderstanding with mass spring systems.