1. The problem statement, all variables and given/known data A spring whose stiffness is 3500 N/m is used to launch a 4 kg block straight up in the classroom. The spring is initially compressed 0.2 m, and the block is initially at rest when it is released. When the block is 1.3 m above its starting position, what is its speed? 2. Relevant equations System: block, spring and earth. delta_Uspring + delta_Ugravitation + delta_K=0 3. The attempt at a solution everything i've tried seems to be wrong, the answer answer given to us however is 3.09 m/s.