DispersionHardQuestion 31389
Question
For transverse waves on a string, in the long-wavelength limit (kL << 1 for a beaded string), the dispersion relation is:
- Aω = vk (non-dispersive)Correct
- Bω = Ak² (dispersive)
- Cω = constant
- Dω ∝ 1/k
Correct answer
ω = vk (non-dispersive)
Explanation
For a continuous string (or beaded string with λ >> bead spacing), the wave is non-dispersive: ω = vk = k√(T/μ). Dispersion (ω vs k non-linear) appears at short wavelengths comparable to the bead spacing.