Sound and Color

Question 1

propagation:

Answer 1

The movement of the waves

Question 2

the denser the rope, the (slower/faster) the speed of the propagation

Answer 2

slower

Question 3

the higher the tension, the (higher/lower) the speed of the propagation on the string

Answer 3

higher

Question 4

is light an electromagnetic wave?

Answer 4

yes

Question 5

What is periodic motion? (T)

Answer 5

the time it takes for a motion to repeat (unit=secs)

Question 6

frequency (f)

Answer 6

the rate at which the motion repeats (units= 1/sec, or Hz)

Question 7

wavelength

Answer 7

the distance wave travels during one period

Question 8

what are the 3 characteristics of color?

Answer 8

hue: what the color is
saturation: how ‘pure’ the color is. The less white, the more saturated, color purity
brightness: how dark or light the color is

Question 9

Additive color mixing

Answer 9

the mixing of light, almost all colors can be produced through mixing 3 primary colors (R, G, B)

Question 10

when R, G, and B are mixed in equal amounts, they produce what color?

Answer 10

white

Question 11

what are the complementary colors of R, G, and B?

Answer 11

R - cyan
G - Magenta
B - yellow

Question 12

How do you make white with complementary colors?

Answer 12

two colors, when added in equal amounts, equal white.
ex. Red + cyan =white

Question 13

what do variables r, g, b stand for? What is their sum?

Answer 13

these are fractions of R, G, B. They add up to 1

Question 14

What are secondary colors?

Answer 14

equal mixtures of 2 primary colors

Question 15

Color triangle rule:

Answer 15

when you add 2 colors, the resulting color always lies on the line joining the colors
ex. yellow = 1/2g +1/2r
cyan = 0r +1/2g

Question 16

Where is additive color mixing used in?

Answer 16

projectors, music displays, television

Question 17

what is the r, g, b for white?

Answer 17

all are 1/3

Question 18

where is gray on the color triangle?

Answer 18

the same place as white

Question 19

which element does the color triangle not indicate?

Answer 19

intensity

Question 20

What are the low intensities of orange, white, and green?

Answer 20

orange–brown
white–gray
green–olive

Question 21

What are the wavelengths for blue, green, and red?

Answer 21

blue: 400-500
green: 500-600
red: 600-700

Question 22

what does red reflect and absorb? green? blue?

Answer 22

red absorbs green and blue, it reflects red
green absorbs red and blue, reflects green
blue absorbs red and green, it reflects blue

Question 23

what is transmittance?

Answer 23

the fraction of light incident on the filter that passes through

Question 24

formula for net transmittance?

Answer 24

T =Ta x Tb

Question 25

what are the subtractive primaries? C + M =? M + Y =? Y + C=?

Answer 25

subtractive primaries: cyan, yellow, and magenta 1. B 2. R 3. G

Question 26

what is the reflectance eqn? What do you use it for?

Answer 26

R = Ra x Rb; you use it for pigments (paints)

Question 27

what is low lightness orange?

Answer 27

brown

Question 28

When two orange filters are put together, what color do they make?

Answer 28

reddish-orange

Question 29

optional: sky blue + orange = ? purple + purple = ?

Answer 29

1. sat. orange (brown) 2. blue

Question 30

where does light come from? What is the Quantum nature of matter?

Answer 30

atoms and molecules can absorb or emit light with discrete wavelengths

Question 31

what is a spectrum?

Answer 31

an atomic 'fingerprint' used to identify atoms

Question 32

describe light emission from atoms:

Answer 32

atoms emit radiation at certain frequencies emission patterns are unique to atoms

Question 33

What is periodic motion? What is an example?

Answer 33

motion that repeats in time; a swing

Question 34

What is fundamental property?

Answer 34

how long it takes for a motion to repeat, the period of the motion

Question 35

Period (T)

Answer 35

time it take for a motion to repeat

Question 36

Frequency (f)

Answer 36

the rate at which the motion repeats

Question 37

Simple harmonic motion

Answer 37

the periodic motion described by a sine function

Question 38

what is frequency in music?

Answer 38

the pitch you hear (what note)

Question 39

What is amplitude in music:

Answer 39

a measure of intensity of sound.

Question 40

What is the formula for volume?

Answer 40

(amplitude)^2

Question 41

What is Hooke's Law? Define the variables

Answer 41

the amount of force exerted by a spring F = k x X k= spring constant X = amount spring is stretched or compressed

Question 42

Oscillation frequency for spring, define the variables.

Answer 42

f = 1/2(pi) x sqrt(k/m) k = spring constant m = mass

Question 43

increasing the spring constant ____ the oscillation freq, decreasing the spring constant ____ the oscillation freq,

Answer 43

increases; decreases

Question 44

does the oscillation frequency of a simple harmonic oscillator depend on amplitude?

Answer 44

no

Question 45

formula for the frequency of a tuning fork:

Answer 45

f = 1/ sqrt(m) m= mass

Question 46

what happens when you increase the mass of a tuning fork?

Answer 46

the pitch lowers

Question 47

the propagation speed:

Answer 47

the disturbance moves at a well defined speed

Question 48

wave:

Answer 48

traveling shape in a medium

Question 49

describe sound waves

Answer 49

the are pressure waves formed from a series of compressions and rarefactions compressions: high air pressure rarefactions: low air pressure, changes in air pressure

Question 50

speed formula

Answer 50

speed = d/t d = distance t= time

Question 51

longitudinal waves:

Answer 51

- direction of disturbance same as direction of propagation - compression and rarefaction waves - like a slinky - sound waves

Question 52

transverse waves:

Answer 52

- direction of disturbance is perpendicular to propagation - do not require medium for propagation

Question 53

what is the speed of light in a vacuum? What is the speed of sound at 21C in dry air?

Answer 53

3 x 10^8 m/s 344.0 m/s

Question 54

How do you find the speed of sound when it is not 21C?

Answer 54

v = (344 + 0.6 x T) T = temperature in C

Question 55

What is a standing wave?

Answer 55

the sum of two waves of the same frequency that move in opposite directions

Question 56

What is a node?

Answer 56

places where the string/wave never moves

Question 57

What is an antinode?

Answer 57

halfway between nodes, where amplitude of wave is at a maximum

Question 58

Do the locations of the nodes and antinodes change in time?

Answer 58

no

Question 59

wave speed (v) formula:

Answer 59

v = (wavelength)(t) t = time

Question 60

period (T) formula:

Answer 60

T = 1/f

Question 61

The higher the mode, the _______ the number of nodes

Answer 61

greater

Question 62

what is the frequency of a standing wave?

Answer 62

f = v/wavelength

Question 63

What is the frequency of f1, f2, f3

Answer 63

f1 = v/(2L) f2= v/L f3 = 3/(2L)

Question 64

wave velocity on a string (v) formula:

Answer 64

v = sqrt(F/p) F = tension on string p = mas per unit

Question 65

Fundamental frequency of a string (f):

Answer 65

f = v/(2L) x sqrt(F/p)

Question 66

What happens when you double the tension on the fundamental frequency of a string?

Answer 66

it increases by sqrt(2) = 1.41 f = v/(2L) x sqrt(2F/p)

Question 67

Mode with the lowest frequency is called the _____ mode Modes with higher frequencies are called_______

Answer 67

1. fundamental 2. Overtones (aka harmonics)

Question 68

What is the eqn for the harmonic series?

Answer 68

fn = nf1 n=1,2,3...

Question 69

frequency is proportional to

Answer 69

1/L

Question 70

formula for F (tension)

Answer 70

F = kg x 9.8 answer in N (newtons)

Question 71

What is formula for p (mass per unit length)

Answer 71

p = M/L

Question 72

What is the relationship between frequency and tension?

Answer 72

frequency = sqrt(tension) f = sqrt(F)