Physics / core

Reflection

process

The bouncing of a wave off a surface, returning it back into the original medium. How mirrors work, why we can see most objects, and how radar detects aircraft.

This concept is covered in depth in our reflections, symmetry, and congruent figures, with worked examples, practice problems, and common mistakes.

💡 Intuition

Like a ball bouncing off a wall—the wave reverses direction at the boundary.

Core Idea

The angle of incidence equals the angle of reflection, measured from the normal.

🔬 Example

Seeing yourself in a mirror uses light reflection; an echo in a canyon uses sound reflection.

🎯 Why It Matters

How mirrors work, why we can see most objects, and how radar detects aircraft.

⚠️ Common Confusion

Angles are measured from the normal (perpendicular), not from the surface.

Related Concepts

Prerequisites

How Reflection Connects to Other Ideas

To understand reflection, you should first be comfortable with waves. Once you have a solid grasp of reflection, you can move on to refraction and diffraction.

Go Deeper

Want the Full Guide?

This concept is explained step by step in our complete guide:

Symmetry, Rotational Symmetry, and Congruence →

Frequently Asked Questions

What is Reflection in Physics?

The bouncing of a wave off a surface, returning it back into the original medium.

Why is Reflection important?

How mirrors work, why we can see most objects, and how radar detects aircraft.

What do students usually get wrong about Reflection?

Angles are measured from the normal (perpendicular), not from the surface.

What should I learn before Reflection?

Before studying Reflection, you should understand: waves.

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