[SOLVED] velocity of a spring 1. The problem statement, all variables and given/known data [/PLAIN] [Broken] A spring is stretched a distance of Dx = 40.0 cm beyond its relaxed length. Attached to the end of the spring is an block of mass m = 8.00 kg, which rests on a horizontal frictionless surface. A force of magnitude 40.0 N is required to hold the block at this position. The force is then removed. When the spring again returns to its unstretched length, what is the speed of the attached object? 2. Relevant equations http://wug.physics.uiuc.edu/cc/IAState/Phys221/spring08/course%20info/FS.pdf [Broken] 3. The attempt at a solution change in X=.4m mass=8kg F=k*dx calculated k=100N/m w=f*dl work=.5mv^2 v=? projected v=2m/s How come 2m/s is not working for my speed did I make an error?