(i) Vibrations that have been dampened
(ii) Example: When a tuning fork is stroked on a rubber pad, it produces damped air vibrations.
(iii) The frictional force reduces the amplitude of vibrations. The vibrating body’s energy is constantly dissipated as it works against the force of friction. As a result, the amplitude of the signal progressively diminishes.
(iv) When it has used up all of its energy, it stops vibrating.