Wave Properties
A wave transfers energy through a medium without transferring matter.
Amplitude (A)
Maximum displacement from equilibrium
meters
Wavelength (λ)
Distance between two identical points
meters
Period (T)
Time for one complete cycle
seconds
Frequency (f)
Number of cycles per second
Hz
Wave Speed (v)
Speed of wave propagation
m/s
Phase (φ)
Position in the cycle
radians
Core Formulas
Wave Speed
v = fλ
Speed = frequency × wavelength
Period & Frequency
T = 1/f f = 1/T
Wave Equation
y(x,t) = A·sin(kx − ωt)
k = 2π/λ (wave number), ω = 2πf (angular freq.)
Superposition & Interference
When two waves overlap, their displacements add (superposition principle).
Constructive Interference
Waves in phase (Δφ = 0, 2π, 4π...) — amplitudes add.
A_result = A₁ + A₂
Destructive Interference
Waves out of phase (Δφ = π, 3π...) — amplitudes cancel.
A_result = |A₁ − A₂|
Doppler Effect
The perceived frequency changes when source or observer are moving relative to each other.
f_obs = f_s × (v + v_obs) / (v − v_source)
Moving toward each other → higher frequency. Moving apart → lower frequency.