A machine of mass 10 kg is supported on springs which deflect 8 mm under the static load. With negligible damping the machine vibrates with an amplitude of 5 mm when subjected to a vertical harmonic force at 80 per cent of the reasonant frequency. When a damper is fitted it is found that the resonant amplitude is 2 mm. Determine:
- the damping coefficient
- the critical damping coefficient
- damping ratio
- logarithmic decrement
- the damping force