Brainscape's Knowledge GenomeTM

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


See full index

physics > waves > Flashcards

waves Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

progressive wave is
example?

A

oscillation that travels through matter
all transfer energy, but not matter
sound

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

transverse waves? e.g.?

A

oscillations are perpendicular to the direction of energy transfer
em waves

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

longitudinal waves
example

A

oscillations are parallel to the direction of energy transfer
sound

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

amplitude definition
wavelength definition

A

maximum displacement from the equilibrium position
distance on a wave from peak to peak

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

frequency definition

A

the number of wavelengths passing a given point per unit time

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

when is a wave in phase/antiphase

A

in phase= particles oscillating perfectly in step with one another
antiphase= 180 degrees out of phase

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

reflection definition
law of reflection

A

when a wave changes direction at a boundary between two different media
angle of incidence = angle of reflection

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

refraction definition
where will it refract towards the normal?

A

when a wave changes direction as it changes speed (some reflection - partial reflection- will occur)
if it speeds up, it will refract towards the normal

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

what does refraction have an affect on

A

the wavelength but not its frequency
wave slows down - wavelength decreases

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

diffraction definition
diffraction occurs the most when?

A

when waves pass through a gap or travel round an object, they spread out

the size of the gap or obstacle is about the same as the wavelength of the wave

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

What is polarisation

A

The particles oscillate in one direction only- the wave is confined to a single plane

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

Which waves can be plane polarised

A

Transverse
Longitudinal cannot as oscillations already limited to one plane

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

What does partial polarised mean
When does this happen?

A

There are more waves oscillating in one particular plane but the wave is not completely plane polarised
When waves reflect off a surface

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

What is the intensity of a wave
UNITS

A

The radiant power passing through a surface per unit area
Wm-2

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

How to calculate intensity
Intensity and amplitude relationship

A

POWER / Cross sectional area
Intensity directly proportional to amplitude squared

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

order of the em spectrum (biggest wavelength to smallest wavelength)
Properties

A

1.Radiowaves 10’2low freq, high wavelength
2.Microwaves 10-2
3. Infra red 10-4
4. Visible light 400-700nm
5.Ultraviolet 10-8
6.X-rays 10-10
7. Gamma rays 10-12
High freq, low wavelength High E (dangerous)

17
Q

properties of em waves

A

Can be reflected, rarefracted and diffracted.
Can be plane polarised.
Travel at the same speed through a vacuum

18
Q

What is the relationship between rarefractive index and the normal

A

The higher the rarefactive index, the closer the refracted line to the normal

19
Q

What is total internal reflection

A

When light strikes a boundary and all the light is reflected back into the original medium

20
Q

What are the two condition required for total internal reflection

A
  1. Light must be travelling from a medium with a higher refractive index into a medium with a lower refractive index.
    2.Angle that the light strikes the boundary must be above the critical angle
21
Q

Angle of * at a * that produces

What is a critical angle

A

The angle of incidence at a boundary between two different media that will produce an angle of refraction of 90 degrees

22
Q

what does superpose mean and principle of superposition

A

when waves overlap
When two waves meet at a point the resultant displacement at that point is equal to the sum of displacements of the individual points

23
Q

difference between superposition and interference

A

interference is when the waves continuously pass through each other

24
Q

difference between constructive and destructive interference

A

constructive is when the two waves are in phase
destructive is when the waves are in antiphase

25
Q

coherence definition

A

waves emitted from two sources that have a constant phase difference

26
Q

difference between path difference and phase difference

A

path difference to do with the distance travelled
phase distance to do with how out of sync the waves are - degrees

27
Q

describe youngs double slit experiment

A

Used a monochromatic source of light and a narrow slit to diffract the light.
Light diffracting from the single slit reaches the double slit in phase, which then diffracts again

28
Q

how is a stationary wave formed

A

when two progressive waves with same frequency and amplitude, moving in opposite directions superpose (which means overlap) to create nodes and antinodes which do not move

29
Q

what is a node

A

a point on a wave with no displacement at all times

30
Q

what is an antinode

A

point on a wave that oscillates with maximum amplitude

31
Q

(in sound and microwaves)

where is the energy in stationary waves

A

SOUND- silence at nodes, maximum volume at antinodes
MICROWAVE - no heating at nodes maximum heating at antinodes

32
Q

Fundamental wave (on a rope) properties

A

1st Harmonic
F0 frequency
Wavelength 2L
A
N. N

33
Q

Fundamental wave (1 end open) properties

A

1st harmonic
F0 frequency
Wavelength 4L
A
N

34
Q

How do the harmonics on a wave 1 end open differ from harmonics of wave on a rope

A

Harmonics wave on a rope increase by 1
Harmonica 1 end open only have odd harmonics

35
Q

Fundamental wave (both ends open) properties

A

1st harmonic
F0
Wavelength 2L
A A
N

36
Q

How to test polarisation

A

2 polarising filters one horizontal one vertical should have 0 intensity

37
Q

Time period

A

time taken for one complete oscillation

38
Q

Polarisation of microwaves practical

A

Place a metal grille in between a microwave receiver and a microwave transmitter. Slowly rotate the grille. Voltage across receiver will be ,maximum when the microwaves pass through the grille

physics (10 decks)

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