1. The problem statement, all variables and given/known data A spring with spring constant K is compressed by x and used to shoot a ball of mass m into an initially stationary block also of mass m. The ball sticks to the block after the collision. Calculate the final velocity of the ball + block. 2. Relevant equations 3. The attempt at a solution F=kx m1v1 + m2v2 = (m1+m2)v2 1/2mv^2 + 1/2kx^2 = (m1+m2)v2 v2 = 1/4v1^2 + kx^2/4m i think my value for the spring's energy is wrong and that messed everything up??