Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AS Physics 6-9 > 6+7: Waves and Quantum behaviour > Flashcards

6+7: Waves and Quantum behaviour Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
0
Q

Constructive Interference

A

Crest+crest =big crest

Trough +trough =big trough

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Superposition

A

When two or more waves cross the resultant displacement equals the vector sum of the individual displacements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Destructive interference

A

Trough+equal sized crest=Nothing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Incomplete destructive interference

A

Trough+ a different sized crest =not total destructive interference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Waves in phase

A

Both on same point in the wave cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Exactly out of phase

A

Phasers point in opposite directions, are at 180 degrees to eachother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Waves are coherent if

A

They have the same wavelength

And frequency and a fixed phase difference between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Number of wavelengths to be in phase

A

Whole number of wavelengths difference apart only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Standing wave

A

The superposition of two progressive waves with the same wavelength moving in opposite directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Standing waves are different from normal waves because

A

No energy is transmitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Nodes

A

The amplitude of the vibration is zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Antinodes

A

Points of maximum amplitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lowest possible resonant frequency (fundamental frequency)

A

One loop- half a wavelength

A node at each end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Second harmonic (first overtone)

A

Two loops with a node at the centre at at the ends

One wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Third harmonic (second overtone)

A

1.5 wavelengths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Pipe closed at one end

A

L= 1/4 wavelength

Node at closed end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Open pipe

A

Antibodies form at open ends of the pipe

L= 1/2 wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Speed of sound using a resonance tube

A 
Tuning fork(labeled with a frequency)
Fill tube with water and find shortest distance that the sound if fork resonates at
This is 1/4 wavelength

Use v=fL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A progressive waves amplitude

A

All points have the same amplitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Diffraction with a big gap

A

no diffraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Diffraction with a medium gap

A

lines are straight with curved edges, still getting bigger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Diffraction with a small gap

A

completely curved lines, getting bigger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

why you can hear but not see someone round a door

A

you can’t see someone round a door because the gap is much bigger than its wavelength
You can hear someone because the wavelength is similar to the width of the gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

the narrower the slit

A

the wider the diffraction pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the brightest point of diffraction is

A

the brightest point of diffraction is where light passes in a straight line from the slit to the screen as all the light that arrives there is in phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

all the other bright spots (other than the brightest)

A

a constant phase difference, the phasors point in slightly different directions and thus have a smaller resultant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

dark fringes

A

phase difference add to give a resultant of zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

coherent sources

A

same wavelength and frequency (made with the same oscillator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

to make two coherent sources with light

A

one laser light (monochromatic as only one wavelength present) source and two equal slits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

to find the fringe spaceing you use the equation

A

wavelength= xd/D
x- fringe spacing
d- spacing between slits
D- distance from slits to screen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is a diffraction grating

A

youngs double slit experiment but with many slits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

the angle between the incident beam and the nth order maxima is given by

A

sin@ = nL/d

n- nth order maxima (which line after the center one)
L-wavelength
d- distance between slits on grating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

where the diffraction equation comes from

A

at each slit light is diffracted, each light ray interferes with each other and produce and interference pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the larger the wavelength

A

the more the pattern will spread out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

if d is bigger

A

sin@ i smaller, the coarser the grating the less the pattern will spread out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

sin@ >1

A

impossible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

speed of light

A

3x10^8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

photoelectric effect

A

free electrons on the surface of a metal absorbs lights’s energy, if it absorbs enough energy it can break free

39
Q

photoelectrons are emitted if

A

the radiation has to be above the threshold frequency

40
Q

energy carried is proportional to

A

the intensity of the beam

41
Q

EM waves can only be released in

A

discrete packets called photons

42
Q

Energy carried by a photon=

A

E=hf =hc/L

h-planck’s constant 6.63x10^-34
L- wavelength
c- speed of light 3x10^8

43
Q

Planck’s constant (h)

A

6.63 x10^-34

44
Q

the higher the frequency of a photon

A

the more energy it carries

45
Q

work function energy

A

the amount of energy required to break the bonds holding an electron there

46
Q

line emission spectra

A

light from hot gass is split with a prism or a diffraction grating

47
Q

continuous spectra

A

if white light is split up with a prism the colors merge into each other (no gaps in the spectrum) to f

48
Q

line absorption spectra

A

light with a continuous spectrum of energy (white light) passes through a cool gas.
Black lines will appear in the continuous spectra from where wavelengths have been absorbed by the gas
these will match up with the colored lines in a line emission spectra

49
Q

to find the right energy level to what it is excited by

A

do n=1-given energy= energy at which it is excited

n=1 is ground state

50
Q

probability of a quantum arriving

A

(resultant phasor)^2

51
Q

how to find the frequency of rotation of a photon phasor

A

f= E/h

52
Q

what happens the longest of the possible phasor paths

A

they curl up and cancel eachother out

53
Q

the final phasor of the quickest past contributes the most

A

to the resultant amplitude and the probability of a quantum arriving at a point

54
Q

when light travels in water

A

slows down
keeps the same frequency
energy stays the same
phasor will still have the same amplitude and frequency rotation whatever material the light is traveliing through

55
Q

What is a concave mirror for

A

to make sure that no matter what point of the mirror the phasor hits it will have taken the same time( travelled same distance) when it reaches the focal point of the mirror

56
Q

What is a convex lens for

A

light hiting the thin glass on the edge takes longer than the light hitting the centre. Beacause the light travels slower through the thicker glass the light emergest at the same time, they converge at a focus point

57
Q

wavelength using Planck’s constant (as Quantum objects) De Broglie equation

A

L= h/mv

58
Q

frequency using kinetic energy and Planck’s constant

A

f= e/h

59
Q

Planck’s constant

A

6.63x10^-34

60
Q

If you increase the electron speed

A

diffraction pattern circles squish together

61
Q

a shorter wavelength gives

A

less diffraction effects

62
Q

To resolve tiny detail in an image you need

A

a shorter wavelength
light blurs out detail more than electrons do
electron microscopes can resolve finer detail than a light microscope

63
Q

How do you know electrons show quantum behaviour

A

accelerated electrons in a vacuum tube interact with the spaces in a graphite crystal
as an electron hits a fluorescent screen, it causes a photon to be released
you can see a diffraction pattern

64
Q

electron mass

A

9.11 x 10^-31

65
Q

power

A

energy/time

66
Q

signals sound the same pitch

A

same fundamental frequency
same period of waveform
lowest frequency

67
Q

number of photons per second

A

energy/power

68
Q

why some places have bad signal

A

waves from two transmitters interfere destructively

69
Q

the smallest separation between two places with bad signal

A

1/2 the wavelength

70
Q

what causes a signal received to fall

A

the incident and reflected rays interfere destructively

71
Q

the signal variation between maxima and minima

A

reflected wave path length changes
incident is unchanged
phase difference change4s
from out of phase to in phase

72
Q

minima

A

lowest resultant wave (no wave formed) after superposition

73
Q

number of electrons=

A

power / energy

74
Q

units for Ke

A

Kgm^2 s^-2

75
Q

units for Force

A

Kgms^-2

76
Q

graph speed from rest falling / time

A

straight line

77
Q

graph of speed falling from rest / distance

A

curve getting less steep

78
Q

TRUE OR FALSE

More than one photon must reach the point at once if there is to be destructive interference

A

FALSE

79
Q

Why can you use S=d/t for a package dropped from a plane for horizontal

A

moving horizontally with the plane
no horizontal force (Acceleration)
horizontal component not affected by gravity

80
Q

How standing waves form

A

waves reflect at ends
travelling both directions
they superimpose (interfere) and constructively and destructively
creates Nodes and AntiNodes

81
Q

Meaning of Frequency

A

How many vibrations in a second

82
Q

units for ENERGY

A

J / Nm

83
Q

number of photons=

A

total energy / energy of one photon

84
Q

difference between probability proportional to

A

difference between light intensity

difference in amplitude^2

85
Q

a graph with equation x= 1/y has shape

A

a negative gradient drooping inwards (almost following the axis)

86
Q

Power

for speed and stuff x2

A

Force x velocity

mass x acceleration

87
Q

Force against resistive forces

A

Friction

88
Q

example of standing waves

A

wind instrument
microwaves
string instruments

89
Q

why would a 0th order maxima appear yellow

A

made up of other colour wavelength

colours dont split up by diffraction

90
Q

when cant there be a second order maxima

A

sin@ cant be bigger than 1

91
Q

charge is (similar to energy)

A

Joules of energy being transferred

92
Q

energy charge voltage =

A

v= e/Q

93
Q

time period is

A

the time for one wavelength

AS Physics 6-9 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions