Reflection and Refraction

This lesson covers the reflection and refraction of waves, including the laws of reflection and Snell's law qualitatively, as required by the AQA GCSE Physics specification (4.6.1). Understanding how waves behave when they meet a boundary between two different media is fundamental to topics including optics, sound, and seismic waves.

---

Reflection of Waves

Reflection occurs when a wave bounces off a surface. When a wave hits a boundary (such as a mirror, wall, or the edge of a ripple tank), it is reflected back.

The Law of Reflection

The law of reflection states:

The angle of incidence equals the angle of reflection.

In symbols: angle i = angle r

graph TD
    subgraph "Law of Reflection"
        N["Normal (perpendicular to surface)"]
        I["Incident ray"] -->|"angle i"| P["Point of incidence"]
        P -->|"angle r"| R["Reflected ray"]
        P --- S["Mirror / reflecting surface"]
    end

Key Definitions