Energie in eenvoudige harmonische beweging

Consider a block of mass m attached to a spring with force constant k on a frictionless surface at equilibrium.

When the block is displaced, the work done by the spring force along the displacement from its initial to final position equals the amount of potential energy stored in the spring relative to its displacement. This is called elastic potential energy.

When released, the block undergoes simple harmonic motion. The energy required for its back-and-forth movement is called translational kinetic energy, and is directly proportional to the square of its velocity and its mass.

During oscillations, both energies continuously interchange and are represented by sinusoidal waveforms. The elastic potential energy is at maximum at the maximum displacement, while the translational kinetic energy is at maximum at the equilibrium position.

At other positions, the block has different kinetic and potential energy values, and their sum equals the system's total energy.

So, the total energy in the system remains constant and conserved, as it oscillates between translational kinetic energy and elastic potential energy.