Which characteristic of a wave remains constant when it travels from one medium to another with different properties?
**Displacement relation** encodes λ = 2π/k and f = ω/2π. Comparing given equation y = a sin(kx - ωt) with standard form yields k and ω, hence λ = 2π/k and v = ω/k, essential for identifying propagation characteristics and phase. When a wave crosses a boundary between media, its speed and wavelength change due to differing medium properties, but frequency remains constant as it is determined by the source. Using v = fλ and standing-wave condition fₙ = n v/(2L) or v/(4L) as applicable, calculation yields Frequency, illustrating frequency-length-speed interdependence and quantization by boundaries.
Ref: NCERT > Physics Book > Waves > Wave Equation and Displacement Relation