Oscillations and Waves

1. Oscillations and Waves Forced Oscillations and Resonance

2. Damping • - Caused by resistive forces that always oppose motione.g. friction • Energy is dissipatedby 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.

4. under critical over • 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

5. 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 bodycauses 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.

6. Physics Resonance of a text book

7. Resonance of a mass on a spring

9. E.g. The Tacoma narrows suspension bridge • Video clip • E.g.Breaking a wine glass using resonance • You tube clip

10. Subtitle Text

11. Subtitle Text

12. Subtitle Text

13. Subtitle Text

14. Subtitle Text

15. Subtitle Text