A plane elastic wave = ae-yx co, and k are constants, propagates in a homogeneous medium. Find

Question:

A plane elastic wave ε = ae-yx co, and k are constants, propagates in a homogeneous medium. Find the phase difference between the oscillations at the points where the particles' displacement amplitudes differ by η = 1.0%, if γ = 0.52 m–1 and the wavelength is λ = 50 cm.