1. The problem statement, all variables and given/known data A massless spring is hanging vertically. With no load on the spring, it has a length of 0.22 m. When a mass of 0.68 kg is hung on it, the equilibrium length is 0.75 m. At t=0, the mass (which is at the equilibrium point) is given a velocity of 4.88 m/s downward. At t=046s, what is the acceleration of the mass? (Positive for upward acceleration, negative for downward) 2. Relevant equations [itex]\Sigma[/itex]Fy=-k(yeq-y0) [itex]\Sigma[/itex]Fy=may 3. The attempt at a solution The only two forces acting on the mass are the Tension from the spring and weight. So Tsm-(mg)=may I am now stuck wondering if that was a good place to start. Is the traditional way to solve this problem to find the spring constant first?