# Physics - Recall for Chapter 17: Oscillations

> Source: https://ollybritton.com/notes/a-level/physics/recall-questions/chapter-17-oscillations.csv/ · Updated: 2022-04-17 · Tags: physics, school, a-level, stars

## Flashcards

### Equilibrium and angular frequency
##### What is the equilibrium position in an oscillation??
The point at which an object experiences no resultant force.
^equilibrium-position-definition

##### If an object doesn't experience a resultant force in the equilibrium position, what also must be true??
There is no acceleration at the equilibrium position.
^no-acceleration-at-equilibrium

##### How many radians are there in one complete oscillation??
$$
2\pi
$$
^radians-in-one-oscillation

##### How can you calculate the angular frequency of an oscillation??
$$
2\pi f
$$
^angular-frequency-formula-ch17
### Defining simple harmonic motion
##### What are the conditions required for simple harmonic motion??
The acceleration is directly proportional to displacement from equilibrium and in the opposite direction to the displacement.
^shm-conditions

##### What is simple harmonic motion??
When the acceleration of an object is directly proportional to displacement from equilibrium and in the opposite direction to the displacement.
^shm-definition-ch17
##### What is the acceleration of an object undergoing SHM when its displacement is zero??
$$
0
$$
^shm-acceleration-zero-at-equilibrium

##### What is an isochronous oscillator??
An oscillator with a period/frequency that doesn't depend on amplitude.
^isochronous-oscillator-definition

##### What is a fiducial marker??
A visual aid placed at the equilibrium position of an oscillation to make it easier to mark track oscillations.
^fiducial-marker-definition

### Displacement, amplitude and phase
##### For an object in simple harmonic motion, what is the displacement, $x$??
The distance and direction from the equilibrium position.
^displacement-definition-ch17
##### For an object in simple harmonic motion, what is the amplitude, $A$??
Maximum displacement from the equilibrium position.
^amplitude-definition

##### What's the definition of "phase difference" between 2 systems oscillating with the same frequency??
Phase difference is the fraction of a cycle by which one system is ahead of the other, measured in radians.
^phase-difference-definition-ch17
##### What's the equation for the displacement $x$ of an object in simple harmonic motion at time $t$ if the object was released from its max displacement at $t = 0$??
$$
x = A\cos(\omega t)
$$
^displacement-cosine-equation

##### What measures can be taken to improve the accuracy when measuring the time period of simple harmonic motion??
Use multiple oscillations and calculate the average of these repeats.
^improving-time-period-accuracy

### Energy in an oscillator
##### What is the kinetic energy of a simple harmonic oscillator at the maximum displacement??
$$
0J
$$
^kinetic-energy-zero-at-max-displacement

##### How does the total energy in a simple harmonic oscillator vary with time??
It is constant.
^total-energy-constant-in-time

##### At what displacement is the potential energy of a simple harmonic oscillator at a maximum??
When the displacement is at the maximum.
^potential-energy-max-at-max-displacement

##### How can you calculate the total energy of a spring-based simple harmonic oscillator from its amplitude??
$$
\frac{1}{2}kA^2
$$
^spring-total-energy-from-amplitude

### Free oscillations and damping
##### What is a free oscillation??
An oscillation in which no external driving force is present.
^free-oscillation-definition-ch17
##### What causes damping of an oscillation??
An external force opposing motion.
^cause-of-damping

##### What effect does damping of an oscillation have in terms of energy??
It transfers the kinetic energy of the oscillation into other forms, such as thermal.
^damping-energy-transfer

##### What is light damping of an oscillation??
A small damping force causing the amplitude of the oscillations to decrease slowly.
^light-damping-definition

##### What is heavy damping of an oscillator??
A damping force that results in a rapid decrease in the amplitude of oscillations.
^heavy-damping-definition

##### What is very heavy (critical) damping of an oscillation??
A large damping force that prevents any oscillations of the system when it is displaced.
^critical-damping-definition

### Natural frequency, forced oscillations and resonance
##### What is the natural frequency of an oscillator??
The frequency at which oscillations will occur in a system with no external driving forces.
^natural-frequency-definition

##### What are oscillations that occur when there is no external driving forces called??
Free oscillations.
^no-driving-force-means-free-oscillation

##### What is a forced oscillation??
An oscillation in which a (periodic) external driving force is present.
^forced-oscillation-definition-ch17
##### What is the driving frequency in a forced oscillation??
The frequency of the external driving force.
^driving-frequency-definition

##### What is resonance??
When the driving frequency of a forced oscillation is close to the natural frequency of the system, resulting in a large increase in the amplitude of oscillations.
^resonance-definition

##### What is likely to occur when a mechanical system with little no damping resonates??
The amplitude of the oscillations will increase until the object breaks.
^undamped-resonance-breaks-object

##### What occurs in terms of energy during resonance??
There is the greatest possible transfer of energy from the driver to the forced oscillation.
^resonance-maximises-energy-transfer

##### What effect does damping have on resonance??
The amplitude of the resonance peak decreases and occurs at a lower frequency.
^damping-lowers-and-shifts-resonance-peak

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