1. The problem statement, all variables and given/known data 2. Relevant equations I am unsure how to find the value for b) and c). If anyone could tell me how to find these values it would be appreciated. 3. The attempt at a solution To find a) I simply found the slope of the positively slopped line and used Hooke's law equation (Ee =0.5kx2 ). There does not seem to be any permanent deformation in the spring so is there energy lost? My guess is it would be lost to other causes but that still doesn't help me answer b). I am unable to calculate the lost energy to prove that the collision is inelastic (my guess).