For the one-dimensional bar shown in Figure P16–4, determine the natural frequencies of...

For the one-dimensional bar shown in Figure P16–4, determine the natural frequencies of longitudinal vibration using first two and then three elements of equal length. Let the bar have E = 30 × 10⁶ psi, ρ = 0.00073 lb-s²/in⁴, A = 1 in² , and L = 60 in.