Oscillations and Waves
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Transcript of Oscillations and Waves
Oscillations and Waves
Forced Oscillations and Resonance
Damping
- Caused by resistive forces that always oppose motion e.g. friction- Energy is dissipated by these forces. E.g. friction
or magnetic damping can result in kinetic energy being dissipated as heat energy flows from the system.
- Damped systems do not describe SHM.
Degrees of damping- under damped: this means the body will oscillate
before coming to rest at the equilibrium position.
- critically damped: the body will come to rest at the equilibrium position in the shortest possible time, without oscillating.
- over damped: this means the body will take longer to come to rest
undercriticalover
Resonance• Natural frequency: the frequency at which a body
will freely oscillate at if plucked or banged or otherwise set in motion.
• Forced oscillations: these occur when a ‘driver’ oscillating body causes another body (the ‘driven’ body) to oscillate at the same frequency (not necessarily its natural frequency).
• Resonance: This occurs when the forced vibration frequency of the driver is equal to a driven objects natural frequency.
Resonance of a text book
Physics
Resonance of a mass on a spring
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Frequency Adjust
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Frequency range
Outputs
A
power
10Hz 100kHz1kHz 10kHz100Hz
Frequency
8 HzWave
transparent tubeto stop massswingingsideways
E.g. The Tacoma narrows suspension bridge- Video clip
E.g. Breaking a wine glass using resonance- You tube clip
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