Problem 2 . Solve for x(t) in the system shown in Figure P4.5 if f(t) is a unit step. [Section: 4.4]. M=1kg K₁ = 5 N/m f₁ = 1 N-s/m f(r)=(r)N 0000 fr FIGURE P4.5 x(1) K₁ M fin