Question 3. A mass-spring-damper is modeled as mdt2d2x+fdtdx+kx=f(t) The value of m=80kg,f=12skg, and k=0.6mN Here, the forcing function has dimensions of force (which has units of N or kgs2m ). The variable x is called the displacement. If no external force is applied to the mass-spring-damper, the steady-state value of x is 0 . a. (1 point) What is the damping ratio associated with this system? Use correct units. b. (1 point) If you were to displace the mass by 0.02 from its equilibrium position, how would you characterize the response of the mass once you let go? Be as specific as possible. c. (1 point) Is there a natural frequency associated with this system? If so, what is its value in Hz