1. The problem statement, all variables and given/known data A spring is stretched a distance of Dx = 40 cm beyond its relaxed length. Attached to the end of the spring is an block of mass m = 8 kg, which rests on a horizontal frictionless surface. A force of magnitude 20 N is required to hold the block at this position. The force is then removed. 2. Relevant equations W=Fd KE=(.5)(m)(v)^2 KE(final) - KE(initial) = W 3. The attempt at a solution I first found work, which I calculated (20N)(.4m) = 8 J Then I plugged it into: 8 J = (.5)(8kg)(0m/s) - (.5)(8kg)(v)^2 8 = 0 - 4(v)^2 I end up with -(sqrt(2)) or +(sqrt(2)), but neither of those are correct. Any ideas with what I am doing wrong?