Week 8 Term 2 2021

Week 9 Term 2 2021 

Homework

• Act 5A, p,53-54, Pulses and Waves
• Worksheet on Superposition and Reflection
• Act 5B, p. 58, Reflection, Refraction and Diffraction of Waves
• Act 5C, p.63-64, Diffraction and Superposition
• Act 6A, p.69, Plane Mirrors
• Act 6B, p.76-77, Curved Mirrors
• Act 7D p.89-90, Lenses

Lens/Mirror Simbucket - app link

Plane & Curved Mirrors

Lenses

Ray Diagram

Comparing Lens & Mirror

Using Descartes formula for the Lens & Mirror

Term 2 Week 7 2021

 

• Act 15A, p. 173-176, Particles and Half-Life
• Act 16A, p. 181, Nuclear Reactions
• Act 5A, p,53-54, Pulses and Waves
• Worksheet on Superposition and Reflection
• Act 5B, p. 58, Reflection, Refraction and Diffraction of Waves
• Act 5C, p.63-64, Diffraction and Superposition
• Act 6A, p.69< Plane Mirrors

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

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

Cymatics

Cymatics

Cymatics: Hose Pipe Water Experiment

Singing plates - Standing Waves on Chladni plates

Cymatics: Ruben's Tube Vs. Tesla Coil

Sound + Fire = Rubens' Tube

A better description of resonance

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

Refraction Bending Light PhET Application

Snell's Law

• 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?

Total Internal Reflection T.I.R.

What Happens to Lazers Underwater?

Term 2 Week 6 2021

  Homework:

• Act 15A, p. 173-176, Particles and Half-Life
• Act 16A, p. 181, Nuclear Reactions
• Act 5A, p,53, Pulses and Waves
• Worksheet on Superposition and Reflection

Basic Properties of Waves

waves transfer energy through a medium without transferring the medium itself

• Cycle - a basic repeating unit in a wave
• Amplitude A (m) - the distance from the middle point to the top of a crest, or bottom of a trough
• Wavelength 𝜆 (m) - the distance/length of one cycle
• Period T (s = s per cycle) - the time it takes for one cycle to pass a point
• Frequency f (Hz = cycles per second) - the number of cycles that pass in one second

T = 1/f & f = 1/T

• Wave Speed v (ms-1) the speed of a wave

v = 𝜆/T & v = f𝜆

Wave Properties

Frequency & Period

Wave Phase

Pendulum Waves

Longitudinal Waves

particle displacement in the medium is parallel to the direction of wave propagation e.g. sound waves, primary earthquake waves

Transverse Waves

particle displacement in the medium is perpendicular to the direction of wave propagation e.g. light and other electromagnetic waves, secondary earthquake waves

• Superposition of Waves: two waves traveling through each other will not change each other motion in any way, but they will add to one another when they overlap
• Constructive Interference - Reinforcement - In Phase
• Destructive Interference - Cancellation - Out of Phase

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

Term 2 Week 4 2021

  Homework:

• Act 15A, p. 173-176, Particles and Half-Life
• Act 16A, p. 181, Nuclear Reactions

Nuclear Reactions:

• Conservation of Atomic Number
• Conservation of Nucleon Number
• Conservation of Mass-Energy E = Δmc2

E = Δmc2

Nuclear Fusion in the Sun

Binding Energy comes from the change in mass from individual nucleons to being combined into a nucleus. This is energy lost by the nucleons joined together in a nucleus and must be returned in order to separate the nucleons

E = Δmc2

Element formation in Stars Nuclear Fusion

Binding Energy Per Nucleon

Mass Per Nucleon

Nuclear Reactions

Fission Fusion and Radioactive Decay

Fission & Fusion

Natural Nuclear Fission Reactor