Consider a thin disk $($radius of $60$ mm and mass of $0\mathrm{.}8$ kg $)$ that is attached to the end of a $1\mathrm{.}2$ m steel

shaft $(G=80{10}^9\frac{N}{m^2},$ density of $7,500k\frac{g}{m^3})$ with diameter of $0\mathrm{.}02$ m $.$ The disk is subjected to a

harmonic torque of amplitude $12\mathrm{.}5$ Nm at a frequency of $700ra\frac{d}{s}.$ For this problem, the size of the

shaft compared to the size of the disk is considered substantial. For such situations, the equivalent

inertia of the system is computed by:

I$\_$equivalent $=$ I$\_$disk $+1/3*\_\_$shaft

Where the mass moment of inertia of the shaft is $1\mathrm{.}41{10}^{-4}kg-m^2.$

What is the steady$-$state amplitude $($amplitude of the particular solution$)$ of angular oscillation of the

disk? Use radians for units in your solution. Upload your computation as a image or pdf file.