A machine part having a mass of \(2 \mathrm{~kg}\) vibrates in a viscous medium. A harmonic exciting force of \(25 \mathrm{~N}\) acts on the part and causes a resonant amplitude of \(12 \mathrm{~mm}\) with a period of \(0.2 \mathrm{~s}\). Find the damping coefficient.

If the frequency of the exciting force is changed to \(3 \mathrm{~Hz}\), determine the increase in the amplitude of the forced vibrations upon the removal of the damper.