Physics / core
Sound, pulses, and wave transport
Relate oscillatory motion to wave equations, acoustic impedance, dispersion, wave packets, and the physical transport of energy.
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Module 01 core
Sound, pulses, and wave transport
Relate oscillatory motion to wave equations, acoustic impedance, dispersion, wave packets, and the physical transport of energy.
- 01
Derive the linear acoustic equations
Connect compression, pressure gradients, and inertia to the small-amplitude sound-wave equation.
29 min - 02
Sound speed measures a material response
Choose the correct thermodynamic compressibility and compare stiffness with density.
29 min - 03
Pressure, particle velocity, and acoustic power
Calculate active intensity using amplitude conventions and the pressure–velocity phase difference.
29 min - 04
Match sound at a material interface
Derive pressure-amplitude coefficients and check energy conservation at a lossless normal-incidence boundary.
29 min - 05
Find the sound modes of an ideal pipe
Use pressure and particle-velocity boundary conditions to determine pipe resonances and their limits.
29 min - 06
Separate carrier speed from envelope speed
Derive narrow-band group velocity and identify when a pulse spreads or an envelope interpretation fails.
29 min - 07
Predict where a wave packet contributes
Use constructive phase accumulation and stationary-phase asymptotics to connect spectra with observed packets.
29 min - 08
Calculate Doppler shifts relative to the medium
Track moving emission and reception points to obtain the classical acoustic Doppler formula with clear signs.
29 min - 09
See why a smooth wave can steepen into a shock
Follow amplitude-dependent characteristics, estimate their first crossing, and identify the physics missing from a multivalued solution.
29 min - 10
Read the gravity–capillary dispersion relation
Compare gravity, surface tension, and depth to determine surface-wave phase and group speeds.
29 min