Simple harmonic motion and how waves carry energy

Simple harmonic motion is a repeating back-and-forth motion around an equilibrium position, caused by a restoring force that grows with the displacement, like a mass bouncing on a spring or a pendulum swinging through small angles. The time for one full cycle is the period. A mass on a spring has a period that depends on the mass and the spring's stiffness, not on how far it is pulled, and a pendulum's period depends on its length and on gravity, not on the mass of the bob. During the motion, energy changes back and forth between kinetic and potential forms. Waves carry energy through a medium in a similar way: in ripples on a pond or a pulse sent down a rope, each bit of the medium oscillates around its own position while the energy travels outward, so the wave transports energy without carrying the medium along with it.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report