5. A mass of 5 kg is attached to a spring with a spring constant k=20 N/m. The damping constant c=10 Ns/m provides resistance proportional to the velocity of the mass. The system is displaced 0.2 meters from equilibrium and released from rest. (a) Set up the differential equation that models the motion of the mass. (b) Solve the equation to find the displacement y(t) as a function of time. (c) What is the natural frequency and the actual oscillating frequency of this vibration system?