Define the total energy of a simple harmonic system.

The total energy of an SHM system is the sum of its kinetic and potential energy, and it remains constant throughout the oscillation.

When is the kinetic energy of an oscillator at its maximum, and why?

At the equilibrium position (x = 0), because the oscillator has maximum speed there.

When is the potential energy of an oscillator at its maximum?

At maximum displacement , x = ±x 0 , since all the kinetic energy has been transferred to potential energy.

The kinetic and potential energy of an oscillator complete .......... full cycles during one period of oscillation.

The kinetic and potential energy of an oscillator complete two full cycles during one period of oscillation.

Describe the shape of the kinetic energy against displacement graph for SHM.

It is an 'n' shaped curve — zero at maximum displacement and maximum at the equilibrium position (x = 0).

True or False? The total energy of an oscillator undergoing SHM varies as it oscillates.

False. Total energy remains constant ; energy is continuously exchanged between kinetic and potential forms as the oscillator moves.

Define a free oscillation .

A free oscillation is one where there are only internal forces acting (no external forces) and no energy input.

Define a forced oscillation .

A forced oscillation is one acted on by a periodic external force , where energy is given to sustain the oscillations.

What frequency does a free oscillation always vibrate at?

Its own natural (resonant) frequency .

What work does the driving force do in a forced oscillation?

It does work against the resistive force , replacing the energy lost to damping.

Forced oscillations occur at the same frequency as the .......... force.

Forced oscillations occur at the same frequency as the driving force.

True or False? An oscillator vibrating in air, with no external driving force applied, cannot be classed as a free oscillation.

False. Provided there is no external force acting, a vibration in air is still classed as a free oscillation .

Give one practical example of a forced oscillation.

Any one, e.g. a car interior vibrating at high speed, a glass shattering from a high-pitched sound, or a clarinet reed driven by the player's breath.

Damping is the reduction in energy and amplitude of oscillations due to resistive forces on the oscillating system.

What happens to the frequency of a damped oscillation as its amplitude decreases?

The frequency stays constant — only the amplitude decreases.

Name the three degrees of damping.

Light damping , critical damping and heavy damping .

Describe the motion of a lightly damped oscillator displaced from equilibrium.

It oscillates with an amplitude that decreases exponentially with time, e.g. a swinging pendulum.

Describe the motion of a critically damped oscillator, with a practical example.

It returns to equilibrium in the shortest possible time without oscillating , e.g. a car suspension system after a bump.

Describe the motion of a heavily damped oscillator, with a practical example.

It returns to equilibrium without oscillating , but takes longer than critical damping , e.g. a door damper.

In critical damping, the oscillator returns to equilibrium in the .......... time possible without oscillating.

In critical damping, the oscillator returns to equilibrium in the shortest time possible without oscillating.

True or False? Resistive force and restoring force are the same thing.

False. Resistive force opposes the motion (velocity) of the oscillator and causes damping; restoring force is what brings the oscillator back towards the equilibrium position.

Resonance occurs when the frequency of the applied (driving) force on an oscillating system equals its natural frequency , causing the amplitude of oscillations to increase significantly.

What is meant by the natural frequency, f 0 , of an oscillator?

The frequency at which the system oscillates when allowed to oscillate freely , with no driving force.

At resonance, how efficiently is energy transferred from the driver to the oscillating system?

Energy is transferred most efficiently , so the system gains the maximum possible kinetic energy.

A graph of driving frequency against amplitude of oscillations is called a .......... curve.

A graph of driving frequency against amplitude of oscillations is called a resonance curve.

Describe how amplitude changes with driving frequency, f , relative to natural frequency, f 0 , on a resonance curve.

Amplitude increases as f approaches f 0 , reaches a maximum at f = f 0 (resonance), then decreases as f increases further.

State three effects that increasing damping has on a resonance curve.

The peak amplitude decreases , the peak broadens , and the peak shifts slightly to the left of the natural frequency when heavily damped.

True or False? Damping changes the natural frequency of an oscillator.

False. Damping changes the shape and height of the resonance curve, but the natural frequency, f 0 , stays the same .

Give three practical examples of resonance.

Any three, e.g. an organ pipe , radio receivers , a microwave oven , and magnetic resonance imaging (MRI) .

How does a radio receiver make use of resonance?

The radio is tuned so its electrical circuit's natural frequency matches the broadcast frequency, causing resonance that amplifies the signal.

How does a microwave oven use resonance to cook food?

It emits microwaves at a frequency that resonates with water molecules in the food, transferring energy by radiation rather than conduction or convection.

What is the purpose of Barton's pendulums?

They demonstrate resonance: pendulum C , whose length equals that of the driving pendulum X , shows the largest amplitude since its natural frequency matches the driving frequency.

In Barton's pendulums, pendulums with lengths greater than L oscillate .......... out of phase with the driving pendulum.

In Barton's pendulums, pendulums with lengths greater than L oscillate π out of phase with the driving pendulum.

In Barton's pendulums, what is the phase relationship between pendulum C and the driver, and why is this significant?

Pendulum C is 0.5π out of phase with the driver; it is the pendulum with the largest amplitude , since its length equals that of the driving pendulum X.

True or False? A microwave oven cooks food mainly by conduction of heat from the oven walls.

False. A microwave oven transfers energy by radiation , using microwaves that resonate with water molecules in the food.

A LevelPhysicsOCRFlashcards5. Newtonian World & AstrophysicsDamping

Damping (OCR A Level Physics): Flashcards

Exam code: H556

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FrontEnergy in SHM
Define the total energy of a simple harmonic system.

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Cards in this collection (36)

Define the total energy of a simple harmonic system.
The total energy of an SHM system is the sum of its kinetic and potential energy, and it remains constant throughout the oscillation.
When is the kinetic energy of an oscillator at its maximum, and why?
At the equilibrium position (x = 0), because the oscillator has maximum speed there.
When is the potential energy of an oscillator at its maximum?
At maximum displacement, x = ±x₀, since all the kinetic energy has been transferred to potential energy.
The kinetic and potential energy of an oscillator complete .......... full cycles during one period of oscillation.
The kinetic and potential energy of an oscillator complete two full cycles during one period of oscillation.
State the equation for the total energy, E, of a simple harmonic system, defining each term.
$E = \frac{1}{2} m ω^{2} x_{0}^{2}$
where m is mass, ω is angular frequency and x₀ is amplitude.
Describe the shape of the kinetic energy against displacement graph for SHM.
It is an 'n' shaped curve — zero at maximum displacement and maximum at the equilibrium position (x = 0).
True or False?
The total energy of an oscillator undergoing SHM varies as it oscillates.
False.
Total energy remains constant; energy is continuously exchanged between kinetic and potential forms as the oscillator moves.
Define a free oscillation.
A free oscillation is one where there are only internal forces acting (no external forces) and no energy input.
Define a forced oscillation.
A forced oscillation is one acted on by a periodic external force, where energy is given to sustain the oscillations.
What frequency does a free oscillation always vibrate at?
Its own natural (resonant) frequency.
What work does the driving force do in a forced oscillation?
It does work against the resistive force, replacing the energy lost to damping.
Forced oscillations occur at the same frequency as the .......... force.
Forced oscillations occur at the same frequency as the driving force.
True or False?
An oscillator vibrating in air, with no external driving force applied, cannot be classed as a free oscillation.
False.
Provided there is no external force acting, a vibration in air is still classed as a free oscillation.
Give one practical example of a forced oscillation.
Any one, e.g. a car interior vibrating at high speed, a glass shattering from a high-pitched sound, or a clarinet reed driven by the player's breath.
Define damping.
Damping is the reduction in energy and amplitude of oscillations due to resistive forces on the oscillating system.
What happens to the frequency of a damped oscillation as its amplitude decreases?
The frequency stays constant — only the amplitude decreases.
Name the three degrees of damping.
Light damping, critical damping and heavy damping.
Describe the motion of a lightly damped oscillator displaced from equilibrium.
It oscillates with an amplitude that decreases exponentially with time, e.g. a swinging pendulum.
Describe the motion of a critically damped oscillator, with a practical example.
It returns to equilibrium in the shortest possible time without oscillating, e.g. a car suspension system after a bump.
Describe the motion of a heavily damped oscillator, with a practical example.
It returns to equilibrium without oscillating, but takes longer than critical damping, e.g. a door damper.
In critical damping, the oscillator returns to equilibrium in the .......... time possible without oscillating.
In critical damping, the oscillator returns to equilibrium in the shortest time possible without oscillating.
True or False?
Resistive force and restoring force are the same thing.
False.
Resistive force opposes the motion (velocity) of the oscillator and causes damping; restoring force is what brings the oscillator back towards the equilibrium position.
Define resonance.
Resonance occurs when the frequency of the applied (driving) force on an oscillating system equals its natural frequency, causing the amplitude of oscillations to increase significantly.
What is meant by the natural frequency, f₀, of an oscillator?
The frequency at which the system oscillates when allowed to oscillate freely, with no driving force.
At resonance, how efficiently is energy transferred from the driver to the oscillating system?
Energy is transferred most efficiently, so the system gains the maximum possible kinetic energy.
A graph of driving frequency against amplitude of oscillations is called a .......... curve.
A graph of driving frequency against amplitude of oscillations is called a resonance curve.
Describe how amplitude changes with driving frequency, f, relative to natural frequency, f₀, on a resonance curve.
Amplitude increases as f approaches f₀, reaches a maximum at f = f₀ (resonance), then decreases as f increases further.
State three effects that increasing damping has on a resonance curve.
The peak amplitude decreases, the peak broadens, and the peak shifts slightly to the left of the natural frequency when heavily damped.
True or False?
Damping changes the natural frequency of an oscillator.
False.
Damping changes the shape and height of the resonance curve, but the natural frequency, f₀, stays the same.
Give three practical examples of resonance.
Any three, e.g. an organ pipe, radio receivers, a microwave oven, and magnetic resonance imaging (MRI).
How does a radio receiver make use of resonance?
The radio is tuned so its electrical circuit's natural frequency matches the broadcast frequency, causing resonance that amplifies the signal.
How does a microwave oven use resonance to cook food?
It emits microwaves at a frequency that resonates with water molecules in the food, transferring energy by radiation rather than conduction or convection.
What is the purpose of Barton's pendulums?
They demonstrate resonance: pendulum C, whose length equals that of the driving pendulum X, shows the largest amplitude since its natural frequency matches the driving frequency.
In Barton's pendulums, pendulums with lengths greater than L oscillate .......... out of phase with the driving pendulum.
In Barton's pendulums, pendulums with lengths greater than L oscillate π out of phase with the driving pendulum.
In Barton's pendulums, what is the phase relationship between pendulum C and the driver, and why is this significant?
Pendulum C is 0.5π out of phase with the driver; it is the pendulum with the largest amplitude, since its length equals that of the driving pendulum X.
True or False?
A microwave oven cooks food mainly by conduction of heat from the oven walls.
False.
A microwave oven transfers energy by radiation, using microwaves that resonate with water molecules in the food.

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