Coaching Centre
Module 3: Waves and Thermodynamics Notes
How waves carry energy, how sound and light behave, and how heat moves between objects.
Sections
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3A Mechanical and electromagnetic waves Mastered
What a wave is, how waves transfer energy without transferring matter, mechanical waves that need a medium, electromagnetic waves that do not, and the difference between transverse and longitudinal waves.
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3B Wave graphs and the wave equation Mastered
Amplitude, wavelength, period and frequency, displacement-distance and displacement-time graphs and how to tell them apart, predicting particle motion from a snapshot, and the wave equation v = fλ with T = 1/f.
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3C Reflection, refraction and diffraction Mastered
How mechanical waves behave at barriers, boundaries and gaps: the law of reflection, refraction as a change of speed with the frequency fixed, diffraction and how it depends on gap size compared with wavelength, all modelled with wavefronts and rays in a ripple tank.
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3D Superposition, standing waves and resonance Mastered
The principle of superposition, constructive and destructive interference, how two waves travelling in opposite directions make a standing wave with nodes and antinodes, and resonance in mechanical systems, including the effect of damping.
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3E Sound waves, beats and the Doppler effect Mastered
Sound as a longitudinal pressure wave, pitch and frequency, loudness and intensity, the inverse square law for sound intensity, decibels, beats from two close frequencies, and the Doppler effect for moving sources and observers.
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3F Harmonics in strings and air columns Mastered
Standing waves on strings fixed at both ends and in open and closed pipes, the fundamental and higher harmonics, the formulas for their frequencies, why instruments sound different, and the resonance-tube method for measuring the speed of sound.
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3G Images in mirrors and lenses Mastered
The ray model of light, how plane and curved mirrors and converging and diverging lenses form images, the standard rays for ray diagrams, real and virtual images, magnification and the thin lens equation.
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3H Snell's law, total internal reflection and light intensity Mastered
Refractive index and the speed of light in a medium, Snell's law, the practical for measuring refractive index, critical angle and total internal reflection, optical fibres, dispersion, and the inverse square law for light intensity.
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3I Temperature, heat and specific heat capacity Mastered
Temperature and the kinetic particle model, the Kelvin scale, internal energy, heat as energy transferred because of a temperature difference, thermal equilibrium, specific heat capacity and Q = mcΔT, and the practical methods (electrical heating and method of mixtures) for measuring it.
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3J Latent heat and energy transfer Mastered
Changes of state and latent heat with Q = mL, reading a heating curve quantitatively, conduction and the rate equation Q/t = kAΔT/d, convection, radiation, and applying all three to insulation and cooling.
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3K Waves and thermodynamics review Mastered
A summary of Module 3 Waves and Thermodynamics, the key equations and how they connect, key words, and a mixed HSC-style test covering wave properties, wave behaviour, sound, the ray model of light and thermodynamics.