Question

Calculate the wavelength λ in steel of longitudinal harmonic waves that correspond to the commonly-used UT frequency of = 5 Mhz. Longitudinal wave velocity in steel = 5940 m/s and ρ=7800 kg/m³. Then use the use the answer to write the expression for longitudinal traveling waves that are excited by a piezoelectric crystal at the end of a thin semi-infinite steel rod extending in the x direction with a 5Mhz frequency and ± 1 nm vibration amplitude (also in the x-direction).

Plot the displacement (on the y-axis) of the traveling wave found in 1. as a function of x (x-values ranging from 0 to 3λ) at t=0 and t=0.25T

Answer 1