A block is attached to a spring, and the block makes Contact with a frictionless surface. Sketch a graph of the potential energy of the block-spring system as a function of position along with the corresponding system as in Figure. Use this sketch to show how the block can move to the left from a positive position to a negative position and decrease the elastic potential energy of the system.
FIGURE: A. The reference configuration and the origin are set to the position of the block when the spring is relaxed. If the spring is then compressed B. or stretched C. the elastic potential energy of system increases.