Write the conservation of energy equation for this situation and solve it for the speed of the mass as it passes equilibrium. A horizontal spring attached to a wall has a force constant of 900 N/m. A block of mass 1.20 kg is attached to the spring and oscillates freely on a horizontal, frictionless surface as in the figure below. The initial goal of this problem is to find the velocity at the equilibrium point after the block is released. The points of interest are where the mass is released from rest (at x = 5.40 cm) and the equilibrium point, x = 0. x= 5.40 it is 1.31 J x= 0 it is 0 J. I am getting suck on write the conservation of energy equation for this situation. the answer is 1.48 M/S but the only equation I can come up with is 1/2kx^2=1/2mv^2 Nothing is adding up here.