Title: Theory / Unimportant / Art / Musique / Musimathics / 4 Physical Basis of Sound
Tags: fromMath mathToDef defToConstant examplesSwitchExample1
On every note of this deck, unless a note says otherwise:
Chapter: 4

Name: A vector
Definition: A direction and a magnitude.
Page: 97
Section: 2
Denoted by: An arrow, showing the direction, whose length represents the magnitude.

Name: A coordinate system
Definition: Any method of specifying points.
Page: 97
Section: 2

Name: Cartesian coordinate
Definition: A set of vectors set at right angles to each other.
Page: 97
Section: 2

Name: A period
Definition: The time between the begin and the end of an event.
Page: 98
Section: 3.1
Context: Sound wave

Name: The frequency
Definition: The number of time an even occur during a second.
Page: 97
Section: 3.1

Name: Mass
Definition: The quantity of matter contained in an object.
Page: 99
Section: 3.1

Name: Matter
Definition: Anything that occupies space and exhibits inertia.
Page: 99
Section: 3.1

Name: Inertia
Definition: The tendency of a body to impede acceleration.
Page: 99
Section: 3.1

Name: Density
Definition: Mass per unit of distance.
Page: 100
Section: 5

Name: Displacement
Definition: Distance from an origin point.
Page: 100
Section: 5

Name: First backward difference operator
Definition: Operator, making the difference between a value at some time and at the precedent time.
Page: 101
Section: 5
Context: Sound
Notation: \(\Delta\)

Name: Speed
Definition: Ratio of distance to time.
Page: 101
Section: 7

Name: Velocity of an object
Definition: Speed and direction of an object
Page: 102
Section: 8

Name: Instantaneous velocity
Definition: Velocity at a precise moment, by measuring smaller time difference. \(\lim\frac{\delta t}{\delta s}\)
Page: 103
Section: 8

Name: Acceleration
Definition: Change of speed by unit of time.
Page: 104
Section: 10

Name: Newton's second law of motion
Definition: Force= Mass x Acceleration.
Page: 108
Section: 12

Name: A newton
Definition: A force which accelerate one kg of one m/s.
Page: 108
Section: 45

Name: The net force acting on \(o\)
Definition: The sum of the forces acting on \(o\).
Page: 108
Section: 45
Variables: \(o\) an object

Name: Newton's third law
Definition: For every action, there is an equal but opposite raction.
Page: 108
Section: 45

Name: Weight
Definition: Force exerced by the gravity.
Page: 109
Section: 13.1

Name: A normal force
Definition: A force perpendical to surfaces that are in contact.
Page: 109
Section: 13.2

Name: Static frictional force
Definition: The force which opposes starting a move.
Page: 109
Section: 13.3

Name: Sliding frictional force
Definition: The force which slow a move of an object sliding on a surface.
Page: 109
Section: 13.3
Name2: Kinetic frictional force
Typ: Non linear force

Name: A non linear force
Definition: A force which is not proportional to some of its characteristic.
Page: 110
Section: 13.3

Name: Work
Definition: Force times distance.
Page: 110
Section: 14
Index: 26
Typ: Joule

Smaller0: a force perform works on an object
Greater0: a change in the kinetic energy of the object
Page: 111
Chapter: 4
Section: 14.1
Variables: \(o\) an object
Index: 26
Hide middle: yes

Name: Kinetic energy of \(o\)
Definition: \(\frac{mv^2}2\), with \(m\) mass and \(v\) speed.
Page: 111
Section: 14.1
Variables: \(o\) an object
Index: 26
Intuition: The energy due to the speed of the object

Name: Gravitational potential energy of \(o\)
Definition: \(mgh\) with \(m\) the mass, \(h\) the height, and \(g\) the gravitational constant.
Page: 112
Section: 14.1
Variables: \(o\) an object
Index: 26

Name: Conservative forces
Definition: Forces which does not dissipates energy.
Page: 113
https://en.wikipedia.org/wiki/Conservative_force
Section: 16
Definition2: A force with the property that the total work done in moving a particle between two points is independent of the path taken

Name: Nonconservative forces
Definition: Forces which dissipates energy.
Page: 113
Section: 16

Name: Power
Chapter: 4
Page: 113
Represents: Work done per unit of time
Section: 18
Typ: Watt

Name: Transverse wave
Definition: The direction of motion that creates the wave is perpendicular to the direction of wave motion.
Page: 116
Section: 20
Example: waves in water

Name: A longitudinal wave
Definition: A wave such that the direction of motion that creates the wave is the same as the direction of wave motion.
Page: 116
Section: 20
Example: sound waves

Name: Torsional wave
Definition: The direction of motion that creates the wave rotates about the axis of wave motion.
Page: 116
Section: 20

Name: Its amplitude
Definition: The distance from its peak height to its point of zero dislpacement or equilibrium.
Page: 117
Section: 21
Variables: \(w\) a wave

Name: Pressure
Definition: The amount of force applied normal to a surface divided by the area over which it is applied.
Page: 118
Section: 21
Typ: Pascal

Name: Intensity
Chapter: 4
Page: 118
Represents: Energy per unit of time that is flowing across a surface of unit area
Section: 22
Typ: W/m2

Name: Threshold of hearing
Definition: Minimum amount of sound intensity required for a sinusouid to be detected by an average listener in a noiseless environment.
Page: 119
Section: 24

Name: Threshold of pain
Chapter: 1, 4
Page: 3, 119
Section: 1, 24
Significative digit: 120dB
Name2: Limit of hearing
Represents2: Intensity above which sound is registered as (possibly damaging) pain by most of us.

Name: The sound intensity level in decibels of \(I\)
Definition: \(10\log_{10}\frac{I}{I'}\) for \(I'\) some reference intensity.
Page: 120
Section: 24.1
Variables: \(I\) an intensitiy

Question: The reference intensity of recording equipment is
Answer: the limit at which recorded sound is distorted.
Page: 121
Chapter: 4
Section: 24.2

Name: Sustaining instrument
Definition: An instrument which receive energy continuously from the player and produce a continuous output
Page: 115
Section: 19.1
Example: Didgeri-do,
Example2: pip organ,
Example3: string

Question: Microphones measures
Answer: air pressures variation.
Page: 124
Chapter: 4
Section: 24.3

Name: Total mechanical energy of \(s\)
Definition: The sum of its potential and kinetic energy.
Page: 112
Section: 16
Variables: \(s\) a system

Name: Pascal
Abbreviation: PA
Chapter: 4
Page: 118
Section: 21
Typ: N/m2.
s: -2
m: -1
kg: 1

Name: Wave
Definition: Proagation in a medium by displacing differences in force or pressure from one place to another.
Page: 116
Section: 20

Smaller0: frequency
Greater0: period
Page: 99
Chapter: 4
Section: 3.1
Smaller to greater: is the inverse of

Name: Tension
Definition: A force that seeks to pull the two ends of the instrument together
Page: 110
Section: 13.4
Definition2: Tendency of the string to be pulled apart

Name: Force
Definition: An action in a particular direction upon an object
Page: 109
Section: 13
Example: Gravity
Example2: Friction
Typ: Newton
Example3: Air resistance, pressure
Example4: Turning (as in a screew)
normal force, buyancy, tension

Smaller0: \(f\) changes the available energy in a system
Greater0: \(f\) is an external force
Page: 112
Chapter: 4
Section: 13
Variables: \(f\) a force
Smaller to greater: iff

Smaller0: \(f\) changes energy from one kind to another
Greater0: \(f\) is an internal force
Page: 112
Chapter: 4
Section: 13
Variables: \(f\) a force
Smaller to greater: iff

Name: A nonsustaining instrument
Definition: An instrument that receive energy at note onset, and whose sounds last until energy is dissipated
Page: 115
Section: 19.1
Example: piano
Example2: guitar
Example3: banjo
Example4: percussions

Smaller0: intensity
Greater0: the distance to the source
Page: 119
Chapter: 4
Section: 19.1
Variables: \(f\) a force
Smaller to greater: inverse of the square
Greater to smaller: inverse of the square root
Context: Sound

Name: Proximity effect
Definition: higher frequencies
Page: 125
Section: 24.3
Variables: \(f\) a force
Definition2: when it is close to the source
DefType: the fact that microphones ignore
Abbreviation2: intensity

Smaller0: intensity
Greater0: \(\frac{\Delta p^2}{V\delta}\)
Page: 123
Chapter: 4
Section: 24.2
Variables: average pressure variation squared \(\Delta p\)
\(V\) velocity of sound in air
\(\delta\) density of air
Smaller to greater: equals