Light damping: amplitude decays exponentially over many oscillations

Forced Vibrations & Resonance — AQA A-Level Physics

Key Definition

Light damping — Damping where the oscillator completes many oscillations with amplitude decreasing exponentially over time.

The displacementThe distance moved in a particular direction from a starting point. A vector quantity. Measured in metres (m).-time graph shows a sine/cosine curve with gradually decreasing peaks.
The amplitudeThe maximum displacement of a point on a wave from its equilibrium (rest) position. Measured in metres (m). envelope is an exponential decay curve.
The time periodThe time taken for one complete oscillation or wave cycle. Measured in seconds (s). stays constant throughout -- peaks and troughs are equally spaced.
Example: a swinging pendulum in air gradually coming to rest.