1. The problem statement, all variables and given/known data So In the following picture is the problem and its solution (Problem 130) 2. Relevant equations KE =1/2 m v2 x:=w^2x 3. The attempt at a solution I am confused of the fact that the time from the spring touching t2 is T/4-t where T is the period oscillations while t is the time to reach equillibrium position.Is it not supposed to be the sum ? Another one is the final work energy statement , why would there be x32 is it not supposed to be x2 ? Thanks in advance.