Periodic $2($Hand in$)$

The mass$-$spring$-$dashpot below has mass $m=4kg,$ stiffness $k=10000\frac{N}{m},$ and damping coefficient $c=20N\frac{s}{m}.$ What are the three most dangerous resonances $($values of $)?$ The base excitation response can be written in terms of an absolute coordinate x and a relative coordinate $z=x-y.$ Write and compare the first three Fourier amplitudes $x_i$ for the x coordinate and $Z_i$ for the z coordinate, for each of the three resonance cases.