sound

Question 1

Periodic vibration

Answer 1

The cyclical motion of an object about an equilibrium point

Question 2

Cycle / vibration

Answer 2

One complete repeat of pattern

Question 3

Period

Answer 3

Time to repeat one complete cycle

Question 4

Frequency

Answer 4

Number of cycles per time interval

Question 5

What is amplitude

Answer 5

The maximum displacement from the rest position

Question 6

Mechanical wave

Answer 6

Transfer of energy through a material due to vibration

Question 7

Medium

Answer 7

Material that permits transmission of energy through vibrations

Question 8

Elasticity

Answer 8

Property of a medium that returns to its original shape after being disturbed

Question 9

Translational molecular motion

Answer 9

Straight line motion of a molecule typically gases think chem

Question 10

Transverse vs longitudinal wave

Answer 10

Transverse is where the particles vibrate perpendicular to the direction of the flow of energy. Longitudinal is a where the particles vibrate parallel to the flow of energy (C & R)

Question 11

Complex wave motion

Answer 11

Combination of longitudinal and transverse waves

Question 12

Waveform, crest, trough

Answer 12

Waveform is the shape, crest is max point of transverse wave, trough is min point of transverse wave

Question 13

Phase, phase shift, in phase, out of phase

Answer 13

Phase is in a continuous transverse or longitudinal wave, phase shift is a shift of the entire wave along x axis think math, in phase is when two identical waves have the same phase shifts, out of phase is when two identical waves have DIFFERENT phase shifts

Question 14

Simple harmonic motion

Answer 14

Any motion that repeats itself at regular intervals. Amplitude, period and frequency are the same for each oscillation

Question 15

Universal wave equation

Answer 15

V = wave length divided by period
V = wavelength multiplied by frequency

Question 17

What two variables are inverse

Answer 17

Frequency and period.
F = 1/T
T = 1/F

Question 18

What is the speed of sound affected by

Answer 18

The temp in the air

Question 19

Mach number

Answer 19

How many times faster than the speed of sound the object is moving
M = Vo/Vs

Question 20

Sonic boom

Answer 20

Once speed of sound is reached, a shock wave is created

Question 21

Infrasonic vs ultrasonic

Answer 21

Infra is frequencies lower than 20Hz, Ultra is frequencies higher than 20KHz

Question 22

Sound intensity

Answer 22

Measure of the amount of sound energy reaching a unit area in 1s

Question 23

Sound intensity level

Answer 23

Logarithmic scale for measuring. Bels and decibels

Question 24

Sound energy transfer through the three states

Answer 24

Solids are the most effective due to their strong intermolecular forces, gases are the least

Question 25

Superposition of waves

Answer 25

When two overlapping component waves produce a resulting wave. The displacement of each point in the medium is the sum of displacements of each component wave

Question 26

Principle of superposition

Answer 26

If two waves are in phase, resulting amplitude is the sum of both

Question 27

Constructive vs destructive interference

Answer 27

Constructive is when 2+ waves combine to build wave with greater amplitude than the amplitudes of the individual waves. Destructive is smaller amplitude than individual waves

Question 28

Free end vs fixed end

Answer 28

Fixed end waves are reflected when they hit the wall, free end just move opposite direction

Question 29

What happens when standing waves are formed

Answer 29

They’re periodic waves, with the same shape, amplitude and wavelength but they travel in opposite directions in a linear medium

Question 30

Nodes vs antinodes

Answer 30

Nodes are points that don’t move in standing waves, antinodes are maximally vibrating points

Question 31

Natural frequency

Answer 31

Frequency at which resonance or standing waves are produced

Question 32

One, two, three standing waves

Answer 32

1 - fundamental mode 2 - first overtone 3 - second undertone

Question 33

Doppler effect

Answer 33

Moving source of sound

Question 34

Beats

Answer 34

Periodic vibrations in amplitude of a wave caused by superimposing two waves of slightly different waves

Question 35

How to calculate beats

Answer 35

Absolute value of f2 minus f1

Question 36

Tuning forks

Answer 36

As they vibrate they compress and refract. Destructive interference occurs at corners creating quiet regions

Question 37

Factors affecting wave speed

Answer 37

Temperature, state of matter, linear density, tension

Question 38

Geometric wave characteristics

Answer 38

Amplitude, size, shape, wavelength, phase and phase shift

Question 39

How to calculate how many times louder a certain decibel variable is to another

Answer 39

Subtract smaller number from the larger number, convert to bel, and do 10 to the power of that bel number. Example: 15-1 = 14db = 1.4b 10^1.4 =25.119 = 25 times louder

Question 40

How to calculate the sound intensity without given second decibel number

Answer 40

If it’s 8 times louder for example, plug in log8 =0.903 Which is .9 bels louder or 9db louder

Question 41

What specific step do you have to do for echos

Answer 41

Either divide time by two or the total distance by two since it’s an echo and the full distance or time is there and back when you only need to calculate there

Question 42

What measures sound intensity and what measures sound intensity level

Answer 42

Sound intensity = picowatts Sound intensity level = bels or decibels