►x (t) k m F (t) Figure P2.97 *2.99. Compute the response of the system in Figure P2.97 for the case that the damping is linear viscous, the spring is a nonlinear soft spring of the form = k(x): = kx - k₁x³ and the system is subject to a harmonic excitation of 300 N at a frequency equal to the natural frequency (w wn) and initial conditions of xo = 0.01 m and vo = 0.1 m/s. The system has a mass of 100 kg, a damping coefficient of 15 kg/s, and a linear stiffness coefficient of 2000 N/m. The value of k₁ is taken to be 100 N/m³. Compute the solu- tion and compare it to the hard spring solution (k(x) = kx + k₁x³).