An engine has a mass moment of inertia of $3.5 \mathrm{~kg}-\mathrm{m}^2$ and is mounted on a shaft of stiffness $1.45 \times 10^5 \mathrm{~N}-\mathrm{m} / \mathrm{rad}$. If the applied moment has a magnitude of $1000 \mathrm{~N}-\mathrm{m}$, what is the engine's steady-state amplitude at $2000 \mathrm{r} / \mathrm{min}$ when an optimally designed Houdaille damper of mass moment of inertia $1.1 \mathrm{~kg}-\mathrm{m}^2$ is added?