Use a three-element, finite-element model to approximate the forced response of the system of Figure P11.15 when the end of the bar is subject to the excitation of Figure P11.17.

\[ \begin{array}{ll} E=200 \times 10^{9} \mathrm{~N} / \mathrm{m}^{2} & m=1.2 \mathrm{~kg} \\ A=3.5 \times 10^{-5} \mathrm{~m}^{2} & k_{1}=2 \times 10^{6} \mathrm{~N} / \mathrm{m} \\ L=2.5 \mathrm{~m} & k_{2}=1.4 \times 10^{6} \mathrm{~N} / \mathrm{m} \\ ho=7000 \mathrm{~kg} / \mathrm{m}^{3} & \end{array} \]

FIGURE P11.15

FA 8000 N 0.01 0.02 (s) FIGURE P11.17