Brainscape's Knowledge GenomeTM

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


See full index

Physics.Y1_Imported > 11 - Waves 1 > Flashcards

11 - Waves 1 Flashcards

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

What is a progressive wave?

A

A wave that transfers energy through oscillations in a medium.

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

What do progressive waves transfer?

A

Energy

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

What do progressive waves not transfer?

A

Matter

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

Describe a transverse wave.

A

Made up of peaks and troughs.

The direction vibration/oscillations are perpendicular to the direction of energy transfer.

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

Describe a longitudinal wave.

A

Made up of compressions and rarefractions.

The direction of vibration/oscillations are parallel to the direction of energy transfer.

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

Give 3 examples of transverse waves.

A
  • Water waves
  • Electromagnetic waves
  • Waves on a stretched spring (slinky)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give 3 examples of longitudinal waves.

A
  • Sound waves

- P waves (produced by earthquakes)

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

What is displacement?

A

The distance from the equilibrium position in a certain direction (vector)

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

What is amplitude?

A

The maximum displacement from equilibrium position.

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

What is wavelength?

A

The distance between two adjacent points on a wave that are in phase.

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

What is a period?

A

The time taken for a wave to move a whole wavelength past a point.

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

What is frequency?

A

The number of waves that move past a point per unit time.

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

What is wave speed?

A

The distance traveled by a wave per unit time.

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

What is phase difference?

A

Phase difference is the difference between the displacements of particles along a wave or along different waves.

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

What is phase difference measured in?

A

Degrees ( ° ) or radians (𝛑).

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

What is the phase difference when two particles are in phase?

A

0°, 360°, 720°, etc

0, 2𝛑, 4𝛑, 6𝛑 etc

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

What is the phase difference when two particles are in antiphase?

A

180°, 540°, 900°, etc

𝛑, 3𝛑, 5𝛑, 7𝛑 etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does it mean if two particles are in phase?

A

They are both oscillating perfectly in step with one another, they both have the same displacement at the same moment.

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

What does it mean if two particles are in antiphase?

A

They are both oscillating perfectly out of step with one another. When one reaches its maximum positive displacement, the other reaches its maximum negative displacement.

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

What does each horizontal square on an oscilloscope represent?

A

The timebase - a certain time interval. It depends on how the oscilloscope is set.

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

What is the vertical axis on an oscilloscope measured in?

A

Vcm⁻¹

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

What waves can be reflected and refracted?

A

All waves

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

What is reflection and when does it occur?

A

Reflection occurs when a wave changes direction at a boundary between two different media, staying in the original medium.

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

What is the law of reflection?

A

The angle of incidence is equal to the angle of reflection.

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

Give an example of reflection?

A

A ray of light reflecting off a mirrored surface.

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

What happens to the wavelength and frequency of a wave when it is reflected?

A

Nothing - they do not change

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

What is refraction and when does it occur?

A

Refraction occurs when a wave changes speed and therefore direction as it passes from one medium to another.

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

What direction does a wave bend if it slows down when moving from one medium to another?

A

Towards the normal.

29
Q

What direction does a wave bend if it speeds up when moving from one medium to another?

A

Away from the normal.

30
Q

What happens to a wave when it enters a more dense medium?

A

It slows down and bends towards the normal.

31
Q

What happens to a wave when it enters a less dense medium?

A

It speeds up and bends away from the normal.

32
Q

What happens to the wavelength and frequency of a wave when it is refracted?

A

Nothing happens to the frequency but the wavelength changes.

(Use wave equation)

speed decreases, wavelength decreases
speed increases, wavelength increases

33
Q

What affects the speed of a water wave?

A

The depth of the water.

Shallower = slower
Deeper = faster
34
Q

What is diffraction?

A

When waves pass through a gap or around an object, they spread out.

35
Q

What waves can be diffracted?

A

All waves

36
Q

What happens to the wavelength, frequency and speed of waves when they are diffracted?

A

Nothing - they stay the same.

37
Q

What does the amount of diffraction depend on?

A

The relative sizes of the gap/object and the wavelength of the wave.

38
Q

When is diffraction most significant?

A

When the wavelength of the wave and the size of the gap/object are the same.

39
Q

Why do we commonly observe the diffraction of sound but not light?

A

Because the wavelength of sound is larger and so there are many gaps and objects in everyday life that are of a similar size, which means that lots of diffraction takes place. Light has a much smaller wavelength and there are not many gaps in everyday life which are small enough.

40
Q

What does it mean if a wave is plane polarised?

A

All the oscillations are in the same direction (in the same plane).

41
Q

Is light from a filament bulb polarised?

A

No

42
Q

What does it mean if a wave is unpolarised?

A

There are oscillations in multiple directions (multiple planes).

43
Q

Why can you not polarise a longitudinal wave?

A

Because the oscillations are already only in one direction, in the direction of energy transfer.

44
Q

What causes waves to become partially polarised?

A

When transverse waves reflect off a surface they become partially polarised.

45
Q

What does it mean if a wave is partially polarised?

A

There are more waves oscillating in one particular plane, however not all of the waves are so it is not completely plane polarised.

46
Q

What is intensity?

A

The radiant power passing through a surface per unit area.

47
Q

What is the unit of intensity?

A

Watts per metre²

Wm⁻²

48
Q

What is the relationship between intensity and distance from the source?

A

Inverse square.

(area = 4πr² –> radius = distance from source)

Increase distance by 3, decrease intensity by 9.
(x1/9)

49
Q

What is the relationship between intensity and amplitude?

A

Intensity is directly proportional to the square of the amplitude.

Increase amplitude by 3 –> increase intensity by 9.

50
Q

What is can an electromagnetic wave be thought of?

A

Magnetic and electric fields oscillating at right angles to each other.

51
Q

What is a unique property of electromagnetic waves?

A

They can travel through a vacuum.

52
Q

Name the electromagnetic spectrum from longest to shortest wavelength.

A 
Radio waves
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma rays
53
Q

What are electromagnetic waves classified by?

A

Their wavelength.

54
Q

What is the speed of all electromagnetic waves through a vacuum (close enough to air)?

A

3 x 10⁸ ms⁻¹

55
Q

How does a polarising filter polarise electromagnetic waves?

A

They act like a slatted fence, only allowing waves that are oscillating in a certain plane to pass through.

56
Q

What is refractive index?

A

A property of a material which affects how fast light moves through it.

57
Q

What does a high refrective index mean?

A

Light will move slower through the material and therefore will bend further towards the normal.

58
Q

What is total internal reflection?

A

When no light energy is refracted out of the material.

59
Q

When does total internal reflection occur?

A

At the boundary between two different media.

60
Q

What two conditions are required for total internal refraction?

A
  1. The light must be travelling in a medium with a higher refractive index than the refractive index of the medium it meets the boundary of.
  2. The angle at which the light strikes the boundary must be greater than the critical angle.
61
Q

How does the refractive index of a material affect the critical angle?

A

The higher refractive index, the lower the critical angle.

62
Q

What is the approximate wavelength of gamma rays?

A

10^-12

63
Q

What is the approximate wavelength of x-rays?

A

10^-10

64
Q

What is the approximate wavelength of UV?

A

10^-8

65
Q

What is the approximate wavelength of visible light?

A

10^-7

66
Q

What is the approximate wavelength of infra red?

A

10^-5

67
Q

What is the approximate wavelength of microwaves?

A

10^-2

68
Q

What is the approximate wavelength of radiowaves?

A

10^3

Physics.Y1_Imported (16 decks)

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