A system that oscillates can be set into motion or kept moving by an external, repeating force. This lesson introduces forced oscillations, distinguishes driving frequency from natural frequency, and explains why resonance can produce large oscillations.
A system’s natural frequency is the frequency at which it would oscillate when it is not being driven and damping is absent. The frequency of an external periodic force is called the driving frequency. These frequencies do not have to be the same.
All flashcards
Driven oscillator
An oscillator acted on by an external periodic force.
Natural frequency
The frequency of free oscillation when driving and damping are absent.
Resonance
A strong response when driving frequency matches or nears natural frequency.
Damping
The process by which energy is removed from an oscillating system.
Radio tuning
Matching a receiver’s resonance to a broadcast frequency helps distinguish nearby stations.
Quiz questions
How does reducing damping affect a driven oscillator’s resonance curve?Answer: It raises the peak and narrows the frequency range of strong response.
Why can low damping help a radio receiver select a desired station?Answer: It sharpens frequency selectivity, helping separate the chosen station from nearby ones.
How do shock absorbers reduce bouncing in a car suspension?Answer: They convert mechanical energy into thermal energy, reducing oscillations.
How does resonance contribute to magnetic resonance imaging?Answer: Radio waves drive nuclei, mostly hydrogen, and their responses help form images.
Why do engineers consider resonance when designing structures?Answer: Repeated forces can produce large structural motion when driving frequencies approach natural frequencies.
Based on College Physics 2e by Paul Peter Urone, Roger Hinrichs (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.