$2\mathrm{.}8.$ Consider the system in Figure P$2\mathrm{.}8,$ write the equation of motion and calculate the

response assuming $($a$)$ that the system is initially at rest, and $($b$)$ that the system has an

initial displacement of $0\mathrm{.}04$ m $.$

Figure P$2\mathrm{.}8$