Module 3: Waves and Thermodynamics
NSW HSC Physics Year 11
Module Overview
This module explores wave phenomena and thermodynamic principles, covering mechanical waves, sound, and the behaviour of thermal energy in systems.
Indicative Hours: 30 hours
Related Outcomes:
- PH11-10 explains and analyses waves and the transfer of energy by sound, light and thermodynamic principles
Inquiry Questions
What are the properties of all waves and wave motion?
How do thermodynamic principles apply to systems?
Key Concepts
3.1 Wave Properties
Learning Focus
Understand the properties of mechanical waves and wave behaviour.
Content:
- Distinguish between transverse and longitudinal waves
- Define wavelength, frequency, period, amplitude, and wave speed
- Apply the wave equation to solve problems
- Analyse reflection, refraction, diffraction, and superposition
Key Formulas:
| Quantity | Formula |
|---|---|
| Wave equation | \(v = f\lambda\) |
| Period-frequency | \(T = \frac{1}{f}\) |
| Wave speed (string) | \(v = \sqrt{\frac{T}{\mu}}\) |
3.2 Sound Waves
Learning Focus
Analyse sound as a longitudinal wave and understand resonance phenomena.
Content:
- Describe sound as a longitudinal mechanical wave
- Calculate the speed of sound in different media
- Explain resonance in air columns and strings
- Analyse beats and the Doppler effect
Key Formulas:
| Quantity | Formula |
|---|---|
| Speed of sound in air | \(v \approx 331 + 0.6T\) m/s |
| Beat frequency | \(f_{beat} = |f_1 - f_2|\) |
| Doppler effect | \(f' = f\frac{v \pm v_o}{v \mp v_s}\) |
3.3 Thermodynamics
Learning Focus
Apply thermodynamic principles to energy transfer and transformations.
Content:
- Define temperature, thermal energy, and heat
- Apply the specific heat capacity formula
- Explain conduction, convection, and radiation
- Analyse the first and second laws of thermodynamics
Key Formulas:
| Quantity | Formula |
|---|---|
| Heat energy | \(Q = mc\Delta T\) |
| Latent heat | \(Q = mL\) |
| Thermal expansion | \(\Delta L = L_0 \alpha \Delta T\) |
Key Definitions
- Wave
- A disturbance that transfers energy through a medium or space without transferring matter.
- Transverse Wave
- A wave where particles oscillate perpendicular to the direction of energy transfer.
- Longitudinal Wave
- A wave where particles oscillate parallel to the direction of energy transfer.
- Wavelength
- The distance between successive corresponding points on a wave.
- Frequency
- The number of complete waves passing a point per second; measured in hertz (Hz).
- Amplitude
- The maximum displacement of a particle from its equilibrium position.
- Temperature
- A measure of the average kinetic energy of particles in a substance.
- Specific Heat Capacity
- The amount of heat required to raise the temperature of 1 kg of a substance by 1°C.