Forced Oscillations and Resonance
The first pictures show the response of a spring with natural frequency 20 rad/s, driven at 18 rad/s. The graph shows the extension x against time, the animation shows the spring's behavior.
The second animation shows the response of an undamped driven oscillator with natural frequency 4 rad/s as driving frequency changes. The closer the driving frequency is to 4 rad/s, the larger the resulting motion. At 4 rad/s, the oscillator experiences resonance: ever-increasing amplitude.
