Please exaplain this problem?

$5\mathrm{.}33$: A rotating machine is mounted on the floor of a building. Together, the mass of the machine and the floor is $2000$ lb $.$ The machine operates in steady state at $600$ rpm and causes the floor of the building to shake. The floor$-$machine system ean be modeled as a spring$-$mass system similar to the optical table of figure $5\mathrm{.}14.$ Design an undamped absorber system to correct this problem. Mahe sure you consider the band width.

Solution: To minimize the transmitted force, let ${}_a==600rpm.$ Also, since the floor shaves at $600$ rpm $,$ it is assumed that ${}_p=600rpm$ so that $=1.$ Using equation $5\mathrm{.}26,$ with $=0\mathrm{.}1$ yields,

$\frac{{}_n}{{}_a}=0\mathrm{.}8543,1\mathrm{.}1705$

So$,$ the natural frequencies of the combined system are ${}_1=52\mathrm{.}6rpm$ and ${}_2=702\mathrm{.}3rpm.$ These are sufficiently enough away from $600$ rpm to avoid problems.

$6$

So$,$ the mass and stifferess of the absorber are

$m_a={}_m=0\mathrm{.}12000lbm=200lbm$

$k_a=m_a{w}_a^2=2001bm(\frac{slng}{32\mathrm{.}1174lbm})(\frac{6002}{60}{)}^2$

$=24583l\frac{b}{f}t$

$($Ans$)$