2. [25%] For an unit step function input (Figure 2a), the vibration of the mass-spring system is given by 1 1 Xstep(t): = k k cos(wnt) for > 0 and zero initial conditions (x(0) = 0, x(0) = 0). For a, finite, inverted ramp input (Figure 2b) vibration response of the mass-spring system with zero initial conditions is given by 11 xir (t) == [sin(wt) - t] + [1 - cos(wt)] for 01