Term 3 Week 2 2018

Homework

• Ex 3D, p.66--67, Wave Properties
• Ex 3E, p.69-70, Diffration
• Ex 3F, p.73-75 Superposition
• Ex 3G, p.76-78 Two Point Source Interference
• Ex 3H, p.81-83 Waves on a String
• Ex 3I, p.85-87 Wave Refraction on a String
• Ex 3B, p. 47-52, Refraction

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

FibreOptic Cables: How they work?

Term 3 Week 1 2018

Homework

• Ex 3D, p.66--67, Wave Properties
• Ex 3E, p.69-70, Diffration
• Ex 3F, p.73-75 Superposition
• Ex 3G, p.76-78 Two Point Source Interference
• Ex 3H, p.81-83 Waves on a String
• Ex 3I, p.85-87 Wave Refraction on a String
• Ex 3B, p. 47-52, Refraction

Refraction

v1/v2 = 𝛌1/𝛌2 = sin(𝜭1)/sin(𝜭2) = n2/n1

Wave Refraction

n1sin(𝜭1) = n2sin(𝜭2)

Snell's Law (for Light Only)

PhET Refraction application

Apparent position of an object underwater

Refraction of Waves

Snell's Law

v1/v2 = 𝛌1/𝛌2 = sin(𝜭1)/sin(𝜭2) = n2/n1 ← Wave Refraction

n1sin(𝜭1) = n2sin(𝜭2) ← Snell’s Law (light only)

Term 2 Week 10 2018

Homework

• Ex 3D, p.66--67, Wave Properties
• Ex 3E, p.69-70, Diffration
• Ex 3F, p.73-75 Superposition
• Ex 3G, p.76-78 Two Point Source Interference
• Ex 3H, p.81-83 Waves on a String
• Ex 3I, p.85-87 Wave Refraction on a String

PhET Waves on a String App - link

Reflection on A String

Hard Boundary

Wave reflects on opposite side (opposite phase)

Same Amplitude, A

Same Wavelength, 𝛌

Same Wave Speed, v

Reflection on A String

Soft Boundary

Wave reflects on same side (same phase)

Same Amplitude, A

Same Wavelength, 𝛌

Same Wave Speed, v

Refraction on A String

Fast to Slow Boundary

Relation of waves to Incident Wave

Reflected Wave - same speed - same wavelength 𝛌 - opposite phase

Refracted Wave - slower speed - smaller wavelength 𝛌 - same phase

Refraction on A String

Slow to Fast Boundary

Relation of waves to Incident Wave

Reflected Wave - same speed - same wavelength 𝛌 - same phase

Refracted Wave - faster speed - larger wavelength 𝛌 - same phase

Diffraction

• The Bending of Waves Around Corners
• Larger Wavelength, 𝛌 - greater the angle of diffraction
• Shorter Wavelength, 𝛌 - smaller the angle of diffraction
• Also the smaller the gap the greater the angle of diffraction

• Diffraction

Diffraction of Water Waves in a Ripple Tank

Two Point Source Interference

Two Point Source Interference

Double Slit Experiment

PhET Sound Wave Interference - link

PhET Wave Interference - link

Cymatics