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8: Oscillations

• 8.1: Oscillatory Motion
We’ve already encountered two examples of oscillatory motion - the rotational motion and the mass-on-a-spring system. The latter is the quintessential oscillator of physics, known as the harmonic oscillator.
• 8.2: Damped Harmonic Oscillator
So far we’ve disregarded damping on our harmonic oscillators, which is of course not very realistic. The main source of damping for a mass on a spring is due to drag of the mass when it moves through air (or any fluid, either gas or liquid).
• 8.3: Driven Harmonic Oscillator
A mass on a spring, displaced out of its equilibrium position, will oscillate about that equilibrium for all time if undamped, or relax towards that equilibrium when damped. Its amplitude will remain constant in the first case, and decrease monotonically in the second. However, if we give the mass a periodic small push at the right moment in its oscillation cycle, its amplitude can increase, and even diverge.
• 8.4: Coupled Oscillators
A beautiful demonstration of how energy can be transferred from one oscillator to another is provided by two weakly coupled pendulums.
• 8.E: Oscillations (Exercises)

Thumbnail: A picture of the first Tacoma Narrows Bridge. The 1940 Tacoma Narrows Bridge, the first Tacoma Narrows Bridge, was a suspension bridge in the U.S. state of Washington that spanned the Tacoma Narrows strait of Puget Sound between Tacoma and the Kitsap Peninsula. It dramatically collapsed into Puget Sound on November 7 of the same year.