Wavelength, frequency and wavefront representations
≈ 48 minWavelength, frequency and wavefront representations
Wavelength is the distance between consecutive points in phase, such as crest to crest; frequency is the number of complete waves passing a point each second, measured in hertz. Wave speed is related by v = fλ. In a fixed medium, changing frequency changes wavelength inversely because the speed is approximately fixed. A wavefront diagram represents phase and direction, while a displacement-versus-position graph represents displacement at one instant; do not mix their axes. Huygens diagrams can show why a gap becomes a new source of curved wavefronts after diffraction.
Work it through
A sound wave travels at 340 m s⁻¹ with frequency 170 Hz. Its wavelength is λ = v/f = 340/170 = 2.0 m. If the frequency doubles in the same air, wavelength halves to 1.0 m. The speed has not doubled because the medium is unchanged.
Mastery target
Read wave representations, use v = fλ with SI units and connect wavelength-to-gap size to the predicted amount of diffraction.
If wave speed in a medium is constant and frequency doubles, what happens to wavelength?
Name the key physics term from Wavelength, frequency and wavefront representations that best fits the explanation and visual model.
A wave travels at 340 m s⁻¹ and has frequency 170 Hz. What is its wavelength in m?
Which statement corrects a common misunderstanding in Wavelength, frequency and wavefront representations?