Brainscape's Knowledge GenomeTM

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


See full index

physics two > waves > Flashcards

waves Flashcards

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

what do waves transfer

A

energy from one place to another

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

what do displacement distant graphs show

A

displacement - how far from equilibrium point wave has oscillated
distance - how far the wave has travelled from the starting point

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

what is the amplitude of a wave

A

the distance between the same two points on two consecutive waves

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

what is the wavelength

A

the distance one one entire oscillation

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

draw a distance displacement graph

A


|
|———————————————– distance
|
|

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

on a distance time graph instead of one oscillation being the wavelength, what does it represent

A

the time period

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

what do we use distance time and distance displacement graphs to work out

A

frequency

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

what is the equation to work out the frequency

A

f = 1/t
frequency = one divided by time

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

what is the equation to work out the wave speed

A

V = F k(thing)
wave speed = frequency x wavelength

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

what are transverse waves - give examples

A

where the oscillation is perpendicular to the direction of energy transfer ( the way the wave is moving)
- electromagnetic (radio, light)
- ripples and water waves

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

what are longitudinal waves - give examples

A

where the oscillations are parallel to the direction of energy transfer ( the way the wave is moving)
- sound waves
- seismic waves

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

what are the three things that could happen when a wave hits a boundary between two materials

A
  • wave may be absorbed and the energy from the wave will be transferred into the materials energy store
  • wave may be transmitted, when it enters the material it carries on travelling through passing out the other side (refraction)
  • reflected and never enter the material
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the factors that effect what happens when a wave hits a boundary between two materials

A

wavelength and the properties of the material

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

what is the rule for drawing ray diagrams for reflections

A

angle of incidence = angle of reflection

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

draw a ray diagram for a mirror

A

answer on pin board flashcard

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

what are the two different types of reflection

A

specular reflection and diffused reflection

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

what is specular reflection

A

the normals are all in the same direction because the boundary is flat (such as a mirror) you get a clear image

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

what is diffused reflection

A

the normals are all in different directions because the boundary is bumpy (such as paper), light will be reflected in different directions therefore no clear image

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

what is refraction

A

waves change direction when they pass through one medium to another

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

why do waves travel at different speeds in different materials

A

they have different densities, the higher the density the slower the wave

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

what will happen to a wave if it travels at an angle toward a boundary

A

it will be refracted ( the direction will change )

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

why would a wave bend more toward the normal

A

if the wave moves into a material that is more dense

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

draw a ray diagram for refraction

A

answer on pin board flashcard

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

if you shine a white light at a triangular prism what would happen

A

becasue different wavelengths are refracted different amounts, each colour will bend in different directions

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

what are sound waves and what type of waves are they

A

vibrations that pass through molecules of a medium - longitudinal waves

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

if particles are more densly packed what happens to the speed of sound and why

A

increases becasue they vibrations can pass along more easily

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

what happens to wavelengths in high density materials

A

get longer as sound speeds up

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

why can sound be refracted

A

it changes speed when moving from one density to another

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

what else can happen to sound waves other than being refracted

A

reflected and absorbed

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

what is the structure of the human ear and explain how these help the process of hearing

A

sound waves travel through ear canal and reach the ear drum which causes it to vibrate. these vibrations will be transmitted along ossicles through the semi-circular canal and into the cochlea where the vibrations are converted into electrical signals that travel along auditory nerves to the brain

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

what is the average Hz for human hearing

A

20 - 20000 Hz

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

what are seismic waves and why do they occur

A

waves that spread out in every direction travelling through layers of the earth because of earthquakes, volcanoes and explosions

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

what are the two types of seismic waves

A

p - waves and s - waves

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

what are the properties of P - waves and S - waves

A

longitudinal and can travel through solids and liquids. they are also faster

transverse waves and only travel through solids

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

how did seismic waves help scientists, what did they discover and how

A

able to discover the different internal structures by measuring which waves could be detected at different points of the earth.
P - waves could be detected at both solid areas and liquid areas

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

what type of waves are electromagnetic waves

A

transverse

37
Q

what differentiates electromagnetic waves

A

their wavelength and their frequency

38
Q

write out the electromagnetic wave table

A

radio waves — micro waves — infrared — visible light — ultraviolet — x ray — gamma rays

39
Q

what happens to the frequency and wavelengths as you go up the table

A

frequency increase and wavelength decresase

40
Q

give one place where gamma rays come from

A

radioactive decay

41
Q

give one place where visible light, ultraviolet and x rays come from

A

electrons dropping down energy levels

42
Q

give one place where infrared rays come from

A

bonds that are holding together molecules vibrating

43
Q

once in contact with a material what can happen to electromagnetic waves

A

can be reflected, absorbed and transmitted

44
Q

why is it called the electromagnetic spectrum

A

the waves are made up of oscillations and magnetic/electric fields

using electricity in the form of an alternating current

45
Q

what are the properties of radio waves (wavelength and frequency)

A

longest wavelength, lowest frequency

46
Q

how can radio waves be generated and used for communication

A

transmitter is connected to an oscilloscope (this allows us to see the frequency of the alternating current).
once radio wave is generated, it is detected by a receiver where it absorbs the energy and generates another alternating current which is viewed on another oscilloscope

47
Q

what are the three types of radio waves and give a brief explanation

A

long waves - travel huge distances as they are able to bend around the earth, some cant bend but are reflected in earths lonosphere
short waves - short distances for things like Bluetooth
very short waves - they need to be directly transferred between transmitter and receiver

48
Q

what are the two types of microwaves

A
  • ones that aren’t absorbed by water
  • ones that are absorbed by water
49
Q

what are microwaves that aren’t absorbed by water used for

A

communication using satellite as they have to pass through the atmosphere - used for things like satellite tv

50
Q

what are microwaves that are absorbed by water used for

A

microwave ovens and helping to heat food as they get absorbed by the water molecules in the food, transferring their energy to the food, making it warm up

51
Q

where are infrared waves emitted from

A

all objects that have thermal energy

52
Q

if an object is hotter, will it emit more or less infrared radiation

A

more

53
Q

what are the two main purposes of infrared radiation

A
  • infrared cameras - can see animals and people in the dark as they emit infrared radiation which the camera detect
  • cooking - heating of metals to high temperatures to emit infrared radiation which is transferred to food
54
Q

what is visible light used for

A
  • the light we use to see, different colours are different wavelengths
  • communication using optical fibres - pulses of light are reflected
55
Q

what are the main uses of ultraviolet waves

A
  • sun beds
  • security - security pens / passports / bank notes
  • sterilising water - destroying microorganisms
56
Q

what is the main use of X - rays

A

to be able to view the internal structure of objects
- detect broken bones and disease

57
Q

what do x rays get absorbed, transmitted and semi transmitted through in terms of the human body

A

absorbed by bone, transmitted through air such as lungs, semi transmitted through flesh such as heart

58
Q

what are the main purposes of gamma rays

A

medical imaging
radiotherapy
sterilising things like medical equipment and food

59
Q

why can gamma rays sterilise medical equipment and food

A

can kill microorganisms without causing any other damage

60
Q

what do doctors and scientists have to be cautious of when using gamma rays in medicine industry

A

it is ionising radiation and can cause harm to body cells

61
Q

what are the two types of lenses

A

convex and concave

62
Q

what do convex lenses do

A

refract parallel light in toward a single point (focal point)

63
Q

what do concave lenses do

A

refract parallel rays of light outward from the focus point. they disperse light

64
Q

what happens to the power of the lens if there is a shorted focal length, and how can we increase the power

A

it will be more powerful
- make the lens more curved
- use a different material that refracts light better

65
Q

where are images formed

A

at points where all the light rays from a particular object appear to come together

66
Q

what is a real image and how would be describe the image that is formed - give an example where a real image would be formed

A

formed when light rays actually do come together to form an image
- smaller, real, inverted
- looking at a real life object

67
Q

what is a virtual image and how would be describe the image that is formed - give an example where a virtual image would be formed

A

formed when the light rays don’t come together where the image appears to be
- upright, smaller, virtual
- in a mirror

68
Q

what is white light and black light made of

A
  • a combination of wavelengths
  • an absence of colour
69
Q

why do objects appear the colour they do

A
  • the wavelength of the light hitting it
  • the properties of the object
  • these both determine which rays are absorbed, reflected and transmitted
70
Q

define opaque

A

an object that doesn’t transmit any light

71
Q

define transparent and translucent and what is the difference

A

they transmit a lot of light
- transparent is total see through

72
Q

what are colour filters used for

A

used to filter out colours only letting certain wavelengths through

73
Q

what are primary filters

A

allow one primary colour wavelength through

74
Q

what are non primary colours

A

let through wavelength of the colour of the filter and the wavelengths of the colours that can be mixed together to make that colour of the filter

75
Q

what is the best material to absorb and emit radiation

A

matt black surfaces

76
Q

a hotter object will emit more or less infrared radiation

A

more

77
Q

what does the wavelength and intensity of infrared radiation depend on

A

the temperature of the object

78
Q

why do very hot objects emit visible light

A

becasue very hot objects emit shorter wavelengths of radiation

79
Q

what will happen if an object is warmer than its surroundings

A

it will emit more radiation than it absorbs and the temperature of the object will decrease

80
Q

what will happen if an object is cooler than its surroundings

A

it will absorb more radiation that it emits and the temperature of the object will increase

81
Q

how can the earth gain or loose energy

A

if it emits or absorbs radiation

82
Q

how does radiation effect the temperature of the earth

A
  • the sun emits short wavelengths of radiation
  • this travels to the earth
  • some of this radiation is reflected by clouds
  • remaining radiation is absorbed by earth which increases the temp causing the earth to emit infrared radiation back into space
  • some is trapped by greenhouse gasses
83
Q

give two factors that effect the temperature of the earth

A
  • the earths rate of absorption and emission of radiation
  • the amount of radiation emitted back into space
84
Q

what are ultrasounds

A

sound waves with a frequency higher than the limit of human hearing

85
Q

what happens to ultrasounds between two densities

A

partially reflects at the boundary

86
Q

what can ultrasounds produce images of

A

internal organs and foetus’

87
Q

why are ultrasounds safter than X - rays

A

they don’t cause the risk of mutations and therefore the risk of cancer

88
Q

what is the equation to use when determining the distance when using an ultrasound

A

distance = speed x time

physics two (4 decks)

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