Elastic Potential Energy with Spring and Incline (Diagram Included) 1. The problem statement, all variables and given/known data 2. Relevant equations ET = 1/2(m)(V2) + mgh + 1/2k*x2 3. The attempt at a solution ET1 - Wf = ET2 1/2k*x2 - Wf = mgh + 1/2mV2 where, Wf = [(0.53)(2kg)(9.8m/s2)(cos67)](1.3m+0.4m) ^ I used this formula and went through by subbing in all numbers but I get error since you can't square root a negative value. Plus we can assume Height off ground is negligible since it cancels out on both sides of equation.