Waves and Thermodynamics

This lesson comprises eight (8) master classes focusing on:

• Wave properties and behaviour
• Sound waves
• Standing waves and resonance
• Ray model of light
• Transfer/transformation of energy within the system

Content:

PH11-10

What are the properties of all waves and wave motion?

• Conduct a practical investigation involving the creation of mechanical waves in a variety of situations in order to explain:
  • the role of the medium in the propagation of mechanical waves
  • the transfer of energy involved in the propagation of mechanical waves
• Conduct practical investigations to explain and analyse the differences between:
  • transverse and longitudinal waves
  • mechanical and electromagnetic waves
• Construct and/or interpret graphs of displacement as a function of time and as a function of position of transverse and longitudinal waves, and relate the features of those graphs to the following wave characteristics:
  • velocity
  • frequency
  • period
  • wavelength
  • displacement and amplitude
• Solve problems and/or make predictions by modelling and applying the following relationships to a variety of situations:
  • \( v=f \lambda \)
  • \( f=\frac{1}{T} \)

How do waves behave?

• Explain the behaviour of waves in a variety of situations by investigating the phenomena of:
  • reflection
  • refraction
  • diffraction
  • wave superposition
• Conduct an investigation to distinguish between progressive and standing waves
• Conduct an investigation to explore resonance in mechanical systems and the relationships between:
  • driving frequency
  • natural frequency of the oscillating system
  • amplitude of motion
  • transfer/transformation of energy within the system

What evidence suggests that sound is a mechanical wave?

• Conduct a practical investigation to relate the pitch and loudness of a sound to its wave characteristics
• Model the behaviour of sound in air as a longitudinal wave
• Relate the displacement of air molecules to variations in pressure
• Investigate quantitatively the relationship between distance and intensity of sound
• Conduct investigations to analyse the reflection, diffraction, resonance and superposition of sound waves
• Investigate and model the behaviour of standing waves on strings and/or in pipes to relate quantitatively the fundamental and harmonic frequencies of the waves that are produced to the physical characteristics (eg length, mass, tension, wave velocity) of the medium
• Analyse qualitatively and quantitatively the relationships of the wave nature of sound to explain:
  • beats \(f_{beat}=|f_2−f_1| \)
  • the Doppler effect \( f^{\prime}=f \frac{(v_{wave}+v_{observer})}{(v_{wave}−v_{source})} \)

What properties can be demonstrated when using the ray model of light?

• Conduct a practical investigation to analyse the formation of images in mirrors and lenses via reflection and refraction using the ray model of light
• Conduct investigations to examine qualitatively and quantitatively the refraction and total internal reflection of light
• Predict quantitatively, using Snell’s Law, the refraction and total internal reflection of light in a variety of situations
• Conduct a practical investigation to demonstrate and explain the phenomenon of the dispersion of light
• Conduct an investigation to demonstrate the relationship between inverse square law, the intensity of light and the transfer of energy
• Solve problems or make quantitative predictions in a variety of situations by applying the following relationships to:
  • \( n_x=\frac{c}{v_x} \) – for the refractive index of medium \( x \), \( v_x \) is the speed of light in the medium
  • \(n_1 \sin \theta_1=n_2 \sin \theta_2 \) (Snell’s Law)
  • \( \sin \theta_c=\frac{n_2}{n_1} \)
  • \( I_1r^2_1=I_2r^2_2 \) – to compare the intensity of light at two points, \( r_1 \) and \( r_2 \)

How are temperature, thermal energy and particle motion related?

• Explain the relationship between the temperature of an object and the kinetic energy of the particles within it
• Explain the concept of thermal equilibrium
• Analyse the relationship between the change in temperature of an object, and its specific heat capacity through the equation \( Q=mc \bigtriangleup T \)
• Investigate energy transfer by the process of:
  • conduction
  • convection
  • radiation
• Conduct an investigation to analyse qualitatively and quantitatively the latent heat involved in a change of state
• Model and predict quantitatively energy transfer from hot objects by the process of thermal conductivity
• Apply the following relationships to solve problems and make quantitative predictions in a variety of situations:
  • \( Q=mc \bigtriangleup T \), where \( c \) is the specific heat capacity of a substance
  • \( \frac{Q}{t}=\frac{kA \bigtriangleup T}{d} \), where \( k \) is the thermal conductivity of a material

PH11-3

• Employ and evaluate safe work practices and manage risks
• Use appropriate technologies to ensure and evaluate accuracy
• Select and extract information from a wide range of reliable secondary sources and acknowledge them using an accepted referencing style

PH11-4

• Select qualitative and quantitative data and information and represent them using a range of formats, digital technologies and appropriate media
• Apply quantitative processes where appropriate
• Evaluate and improve the quality of data

PH11-6

• Use modelling (including mathematical examples) to explain phenomena, make predictions and solve problems using evidence from primary and secondary sources
• Use scientific evidence and critical thinking skills to solve problems

PH11-7

• Select and use suitable forms of digital, visual, written and/or oral forms of communication
• Select and apply appropriate scientific notations, nomenclature and scientific language to communicate in a variety of contexts
• Construct evidence-based arguments and engage in peer feedback to evaluate an argument or conclusion