A SDOF mass-spring-damper system has m = 1 kg, c = 6 Ns/m, and k = 13 N/m with the initial conditions x(0)=x(0)=0. A step force of 20 N is applied at t = 0. (a)Find the response of the system. (b)Indicate the transient and the steady-state responses. (c)Indicate the natural and forced responses.