Damped & Forced Oscillations, Resonance (Cambridge (CIE) A Level Physics): Flashcards
Exam code: 9702
1/130Still learning
Know0
- FrontDamping
Define damping.
Was this flashcard helpful?
Cards in this collection (13)
Define damping.
Damping is the reduction in energy and amplitude of oscillations due to resistive forces (such as friction or air resistance) acting on the oscillating system.
True or False?
The frequency of a damped simple harmonic oscillator decreases as its amplitude decreases.
False.
The frequency stays constant as the amplitude decreases; only the amplitude reduces due to resistive forces.
How does the amplitude of a lightly damped oscillator vary over time, and give an example of a lightly damped system.
The amplitude decreases exponentially with time, for example a swinging pendulum gradually decreasing in amplitude until it comes to rest.
Describe the motion of a critically damped oscillator when displaced from equilibrium, and give an example.
It returns to the equilibrium position in the shortest possible time without oscillating, for example a car suspension system.
Describe the motion of a heavily damped oscillator when displaced from equilibrium, and give an example.
It returns to equilibrium without oscillating, but more slowly than a critically damped system, for example a door damper.
What is the key difference between the displacement-time graphs of critically damped and heavily damped systems?
Both show no oscillation, but the heavily damped system has a slower decreasing gradient and takes longer to reach zero displacement than the critically damped system.
Define resonance.
Resonance occurs when an oscillating system is forced to oscillate at its natural frequency, producing the maximum amplitude of oscillation.
Define natural frequency.
The natural frequency (f0) is the frequency at which a system oscillates freely, without any external driving force.
What is meant by the driving frequency of a forced oscillation?
The driving frequency (f) is the frequency of the external force causing the forced oscillations.
What happens to the energy an oscillating system gains from a driving force as the driving frequency approaches the natural frequency?
The system gains more energy from the driving force as the driving frequency approaches the natural frequency.
At resonance, how efficiently is energy transferred from the driver to the oscillating system?
Energy is transferred in the most efficient way possible, so the system transfers the maximum kinetic energy possible.
When a child on a swing is given a small push after each cycle, this push creates the .......... frequency, increasing the amplitude of the oscillations.
When a child on a swing is given a small push after each cycle, this push creates the driving frequency, increasing the amplitude of the oscillations.
True or False?
As the driving frequency of a forced oscillation gets closer to the natural frequency, the amplitude always increases to the same maximum extent, regardless of how close the match is.
False.
If the driving frequency does not exactly match the natural frequency, the amplitude increases but not to the same extent as when resonance (an exact match) is achieved.
Sign up to unlock flashcards
or