Reflection of Waves

This lesson covers the reflection of waves, including the law of reflection, how to draw ray diagrams for plane mirrors, and how reflection applies to different types of wave, as required by the Edexcel GCSE Combined Science specification (1SC0).

---

What Is Reflection?

Reflection occurs when a wave bounces off a surface. The wave changes direction but stays in the same medium.

Key points about reflection:

• The speed, frequency and wavelength of the wave do not change during reflection.
• Only the direction of travel changes.
• Reflection can happen with all types of wave — light, sound, water waves, etc.

---

The Law of Reflection

The law of reflection states:

The angle of incidence is equal to the angle of reflection.

$\text{angle of incidence} = \text{angle of reflection}$angle of incidence=angle of reflection

$\theta_i = \theta_r$θi​=θr​

Important Definitions