Brainscape's Knowledge GenomeTM

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


See full index

Eleanor Rowe Physics > Waves > Flashcards

Waves Flashcards

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

What is a wave

A

A vibration of particles that transfer energy

The particles stay in the same place and oscillate (vibrate)

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

What is frequency

A

The number of waves per second

Measured in Hz

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

What are transverse waves

A

Sideways vibrations that are perpendicular to the direction of energy transfer

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

Examples of transverse waves

A

EM waves
Water ripples
Wave on string

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

What are longitudinal waves

A

Parallel vibrations that 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

Example of longitudinal waves

A

Soundwaves ultrasound and seismic waves

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

Equation for wave speed

A

Frequency times wavelength

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

Equation for frequency

A

1/period

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

What happens when waves arrive at a Boundry

A

They are either
Absorbed by the material and transfer their energy to the material
Transmitted so they keep on travelling
Or reflected

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

True or false

Angle of incidence = angle of reflection

A

True

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

What is the normal

A

Align perpendicular to surface at the point of incidence

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

What is specular reflection and where does it occur

A

When a wave is reflected in a single direction occurs on a smooth surface

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

What is diffuse reflection and where does it occur

A

It is when the light is scattered in lots of directions because the normal is different for each ray of light
Occurs on a rough surface

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

Properties of EM waves

A 
Transverse
Transfer energy from source to absorber
All travel at the same speed
All have different frequencies
Form a continuous spectrum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do all EM waves have different frequencies

A

They are generated by a variety of changes in atoms and nuclei

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

What is refraction

A

When waves change direction at a Boundry

It depends on the density of materials

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

If a wave goes through a material that is more dense, what will happen and why

A

It will have a shorter wavelength and bend towards the normal
Slow down

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

What happens when a wave goes through a material that is less dense

A

It will have a longer wavelength will speed up and will bend away from the normal

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

What is optical density

A

How dense and material is and therefore how quickly light can travel through it

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

What are radio waves

A

Oscillating charges of alternating-current absorbed by receiver

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

What are long wavelength radio waves used for and how does it work

A

For communication
They bend around curve of earth
They diffract around hills and tunnels

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

What are short wavelength radio waves used for and how does it work

A

They are reflected by the ionosphere

And transmit Bluetooth signals

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

What is the ionosphere

A

A charged layer in the atmosphere

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

How are TV and FM Radio signals sent and what do they have to be

A

They are very short wavelengths

To receive them you must be in direct sight of the transmitter because it doesn’t bend or travel far through buildings

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

What are microwaves used for and how do they work

A

Satellites- receive microwaves from transmitters then transmit signals to dish on Earth
Food - water in food absorbs microwaves causing the water to heat up which then transfers energy to the rest of the food

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

What is infrared radiation what and what does it do

A

It is given out by hot objects
Detected by infrared cameras
The brighter the hotter the object is
It cooks food as they absorb the radiation
Works as heaters where the wire heats up and current flows through it IR is emitted, making air in room heat up

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

How is visible light used

A

Used to transmit data and fibre-optic cable is made of glass or plastic where the light reflects off the cable and travels through it so it is not absorbed until received

28
Q

What is UV radiation and how does it work

A

Radiation absorbed by fluorescent materials that omit light
Is very energy efficient
Produced by sun making us tan
UV lamps give fake tan but are dangerous

29
Q

How are x-rays used in medicine

A

They show broken bones on a negative image as can’t pass through bone or metal but can pass through flash and aren’t detected

30
Q

How are gamma rays used in medicine

A

Can kill cancer cells but need to be specifically directed as also kill healthy cells
A gamma omitting source for example iodine can be put into the body to show function of thyroid

31
Q

What safety precautions must be taken when using radiation in medicine

A

The radiographer should wear lead apron, stand behind screen or leave room

32
Q

Are low or high frequency EM waves more harmful and why

A

High frequency more dangerous

They cause mutations leading to cancer

33
Q

What is a Sievert and what does it measure

A

Measurement of risk of harm from radiation

34
Q

What do lenses do

A

Refract light to form images

35
Q

What does diverge and converge mean

A

Diverge - spread out

Converge - come together

36
Q

In what case would a convex lens produce a virtual image

A

Of the object is closer than the principle focus

37
Q

Is a magnifying glass concave or convex

A

Concave

38
Q

How does visible light work

A

Made up of a range of colours each with a different wavelength the primary colours are red green and blue

39
Q

What happens if all three primary colours are mixed

A

White light is given off

40
Q

What do opaque objects do to light

A

Don’t transmit light

Just absorb or reflect it

41
Q

What does the colour of an opaque object depend on

A

Which wavelengths it most strongly reflects

Eg Apple appears red because it reflects red light the most

42
Q

What wavelengths do white objects reflect

A

All wavelengths equally

43
Q

What do black objects do to wavelengths of light

A

Absorb them all

44
Q

What do transparent objects do to light wavelengths

A

Transmit light

45
Q

What do coloured filters do to visible light

A

Only let particular wavelengths of light through

46
Q

What do primary colour filters do to light

A

Only allow that colour wavelength to pas through

47
Q

True or false

All objects continually emit and absorb IR radiation

A

True

48
Q

What absorbs and emits more IR black or white

A

Black

49
Q

What absorbs and emits more infrared shiney or Matt

A

Matt

50
Q

What is black body

A

An object that absorbs all radiation that hits it

Is the best possible emitter or radiation

51
Q

Why is the earths temp higher in day than night

A

In day lots of radiation is absorbed from sun

At night less radiation is absorbed

52
Q

What is radiation absorbed or reflected by when coming from the sun to earth

A

Is absorbed or reflected by clouds

53
Q

What are sound waves

A

Longitudinal waves caused by vibrating objects

54
Q

Do sound waves travel fastest in solids or liquids

A

Solids

55
Q

Example of sound waves being produced

A

Paper diaphragm vibrates causing surrounding particles to vibrate, compressing and rarefracting making sound waves

56
Q

Why can’t sound waves travel in space

A

There is no particles to vibrate

57
Q

How are sound waves heard by the body

A

The ear drum vibrates which passes on to the cochlear which sends electrical signals to brain

58
Q

What frequency can humans hear

A

20-20,000 Hz

59
Q

Do sound waves speed up or slow down in denser material

A

Speed up

60
Q

What are ultrasound waves and what do they do at boundary’s

A

They are sound waves with frequency above 20,000Hz

They are partially reflected at boundaries, so can detect how far away an object is

61
Q

Medical use of ultrasound

A

When reach boundary, some is reflected back and detected

Timing and distribution of echoes is processed by computer to form video

62
Q

Industrial use of ultrasound

A

Find flaws in object eg pipes

US reflected by far side of object, if flaw or crack present, will be reflected more

63
Q

Why is it important we study the properties of paths of waves

A

Gives us ideas about structures not seen by the human eye

64
Q

What are seismic waves

A

Waves produced by earthquake

Detected by seismometers

65
Q

What are P Waves

A

Waves that travel through solids and liquids
Travel faster than S waves
Longitudinal

66
Q

What are S waves

A

Transverse waves
Travel through only solids
Show outer core is liquid as mine are detected other side of earth after earthquake

Eleanor Rowe Physics (11 decks)

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