An automobile modeled as a single-degree-of-freedom system free to vibrate in the vertical direction. In a free vibration test the amplitude of oscillation is observed to decrease from 20mm to 2 mm in one cycle which takes 3 seconds. When carrying passengers with a total mass of 300 kg the free vibration amplitude is observed to decay from 20mm to 2.75 mm in one cycle. Find the mass of the vehicle and the stiffness and damping of the suspension system.