Week 6 Term 3 2026 Refraction, Wave Equation, Snell's Law, TIR (Totoal Internal Reflection)

 Homework:

Basic Properties of Waves

• Act 5A, p,53, Pulses and Waves
• Ex 3D, p.66--67, Wave Properties

Superposition & Diffraction

• Ex 3F, p.3F, p.73-75 Superposition
• Act 5B, p. 58, Reflection, Refraction and Diffraction of Waves
• Act 5C, p.63-64, Diffraction and Superposition
• Ex 3E, p.69-70, Diffration
• Ex 3H, p.81-83 Waves on a String

Young’s Double Slit Experiment

• Ex 3B, p. 47-52, Refraction
• Ex 3G, p.76-78 Two Point Source Interference

Reflection, Refraction and Diffraction

• Act 5B, p. 58, Reflection, Refraction and Diffraction of Waves
• Act 7A, p.83-84, Refraction of Light
• Act 7B, p.86, Critical Angle
• Act 7C, p.87, Prisms
• Ex 3B, p. 47-52, Refraction of Light
• Ex 3I, p.85-87 Wave Refraction on a String

Snell's Law & Critical Angle

The Critical Angle occurs when a wave is attempting to pass from a medium with a slower speed to that of a higher speed 

low v → higher v

low 𝜆 → higher 𝜆

high n → lower n

The Critical angle is the incident angle where the refracted angle equals 90 degrees

Any incident above the Critical angle will prevent any refraction occuring and Total Internal Reflection will occur

The Critical angle is can be found by sin(𝜭c) = n2/n1

Refraction Bending Light PhET Application

Snell's Law

FibreOptic Cables: How they work?

Total Internal Reflection T.I.R.

What Happens to Lazers Underwater?