In physics class, we had to do a lab where a mass was attached vertically to a spring system. The spring went through simple harmonic motion. We stretched the mass and let go of it. We then used a software to determine the kinetic energy, the elastic potential energy, and the total energy. We had to predict what the total energy graph would look like. I thought that it should be constant, as according to the law of conservation of energy. However, from the graph that I got from the observations, the total energy increases and decreases. What would be the reason for this? Would human errors have anything to do with this, such as not being able to get the spring to move completely vertically. Would my observations show that the mass and spring system does not follow the conservation of mechanical energy?