Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physics > Waves > Flashcards

Waves Flashcards

1
Q

What are waves? What can they be described as? - Waves

A

Waves are a way in which energy may be transferred between energy stores. Can be described as oscillations about a rest position

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

What is a longitudinal wave? - Waves

A

A wave with oscillations in the same direction as the direction of energy transfer

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

What are transverse waves? - Waves

A

Transverse waves are waves with oscillations at right angles to the direction of energy transfer

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

What are mechanical waves? - Waves

A

Waves which cause oscillations in a solid, liquid or gas (must have a medium to travel through)

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

What are electromagnetic waves? - Waves

A

Waves which cause oscillation in electrical and magnetic fields

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

What are the rest position, peaks and troughs of a wave? - Waves

A

Rest position - undisturbed position of particles when they are not vibrating
Peaks - the highest point above the rest position
Trough - the lowest point below the rest position

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

What are the amplitude, wavelength and frequency of a wave? - Waves

A

Amplitude - the distance between the rest position and the peak/trough
Wavelength - distance covered by a full cycle of a wave, from peak to peak
Frequency - the number of waves passing a point each second

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

How can you calculate the time period of a wave? - Waves

A

Time period (s) = 1 / frequency (Hz)

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

How do you calculate wave speed? - Waves

A

Wave speed (m/s) = frequency (Hz) x wavelength (m)

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

How is sound heard by humans? - Waves

A

Sound causes air particles to vibrate and collide, causing them to vibrate between air particles. These particles enter an ear drum and vibrate the ear drum

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

How can the speed of sound be calculated? (Equation and method) - Waves

A

Speed (m/s) = distance (m) / time (s)
Stand an observer 400 metres away and ensure a sound is made and a hand signalled when it starts. When the sound is heard stop the clock.

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

Name 2 examples of longitudinal waves? - Waves

A

Sound waves, ultrasound waves, seismic P waves

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

Describe the structure of longitudinal waves - Waves

A

Longitudinal waves show areas of compression and rarefactions
Compressions are regions of high pressure due to particles being close together. Rarefactions are regions of low pressure due to particles being spread apart

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

Name 2 examples of transverse waves - Waves

A

Electromagnetic waves (light/radio/micro), ripples on the surface of water, seismic S-waves

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

What type of wave are electromagnetic waves? - Waves

A

Electromagnetic waves are transverse waves. Their oscillations are at right angles to the direction of wave travel

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

Describe the abilities of electromagnetic waves (where they can travel, speed, type of energy) - Waves

A

Electromagnetic waves transfer energy as radiation to an absorber
Can travel through a vacuum like space
Travel at the same speed through vacuum or air

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

What mnemonic helps remember the electromagnetic spectrum? - Waves

A

Randy Men Inject Viagra Until Xplosive Growth

Radio, Micro, Infrared, Visible Light, Ultraviolet, X-Ray, Gamma

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

Why is the visible light group unique? - Waves

A

It is the only wave in the electromagnetic spectrum which is visible to the naked eye

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

What happens to the wavelength/frequency in the electromagnetic spectrum as you go from radio -> gamma? - Waves

A

The wavelength of waves decreases, and the frequency of waves increases

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

What colour of light has the lowest frequency of all the visible light? What has the highest? - Waves

A

The colour red has the lowest frequency of all the visible light. Violet light has the highest

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

What are radio waves used for? Explain why they are useful for this - Waves

A

Radio waves used for communication, TV and radio. They are easily transmitted through air and do not damage humans if absorbed. Can be reflected to change direction

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

What are microwaves used for? Explain why they are used for this - Waves

A

Used for cooking food and satellite comms. They are easily absorbed by food molecules and increase the internal energy of food molecules which heats food. They also easily pass through the atmosphere

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

What are infrared waves used for? Explain why they are used for this - Waves

A

Used by cookers to cook food, electrical heaters. Has frequencies absorbed by some chemical bonds, and increases their internal energy, heating them.

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

What is visible light used for? Explain why it is used for this - Waves

A

Visible light is used in fibre-optic communications. It is visible which means coded light pulses can travel from a source to a receiver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are ultraviolet waves used for? Explain why they are used for this - Waves
Used in energy efficient lamps, as these can absorb ultraviolet rays and re-emit the energy as visible light. Also used to tan skin, as it can be absorbed by humans
26
What are gamma rays used for? Explain why they are used for this - Waves
Gamma rays can be used to reduce cancerous growths. By firing them at a growth from different angles, focussing them at a point they do not damage individual cells, but shrink the growth. High wavelength makes them potent
27
What are x-rays used for? Explain why they are used for this - Waves
Used for internal imaging, as they are easily absorbed by dense structures, meaning that they help identify fractures
28
What is the law of reflection? - Waves
States that the angle of incidence = angle of reflection | If a ray hits a surface at 32° then it will be reflected at 32°
29
How do you measure the angles of incidence and the angles of reflection? - Waves
Measure from the normal (imaginary line at 90° to the reflective surface)
30
What is specular reflection? - Waves
Reflection from a smooth flat surface
31
What is a virtual image? - Waves
An image made from fake rays of light
32
What is a diffuse reflection? - Waves
If a surface is not smooth, then diffuse reflection happens. The reflected rays of light are scattered in all directions, causing a distorted object image
33
Why does refraction occur in light waves? - Waves
Different materials have different optical densities which causes them to change speed upon meeting the dense surface
34
When light passes through a substance denser than air, does it bend towards or away from the normal? - Waves
The light will bend towards the normal if the substance is denser than air
35
For a given frequency of light, what is the relationship between wavelength and wave speed? - Waves
If the frequency of the light remains the same, then the wavelength is proportional to the wave speed
36
What type of waves are sound waves? What does this means? - Waves
Sound waves are longitudinal waves, which means that the oscillations are parallel to the direction of energy transfer.
37
How does the human ear process sound and allow it to be heard? - Waves
Sound waves enter the ear and cause the ear drum to vibrate. 3 small bones transmit these vibrations to the cochlea which makes electrical signals which pass into the brain and are interpreted as sound
38
How does the frequency/amplitude of a sound wave relate to the sound heard? - Waves
A high frequency sound wave is high pitched, and a low frequency sound wave is low pitched High amplitude sound waves are loud, low amplitude sound waves are quiet
39
What is the range of normal human hearing? - Waves
20 Hz to 20,000 Hz
40
What is ultrasound? - Waves
Ultrasound waves have a frequency higher than the upper limit of human hearing
41
What can ultrasound be used for? Explain why it is used for this - Waves
Ultrasound can be used for breaking kidney stones or cleaning jewellery. It can do this due to its high frequency and high pitched sound
42
What are seismic waves? - Waves
Seismic waves are shock waves that travel through the earth usually caused by an earthquake
43
What are the 2 types of seismic waves? Which one is longitudinal, which one is transverse? - Waves
P-waves, which are longitudinal | S-waves, which are tranSverSe
44
Describe whether P-waves and S-waves are slow or fast and whether they can travel through different mediums - Waves
P-waves: faster (PACE), travel through solids and liquids | S-waves: SLOWER, SOLIDS
45
How does the study of seismic waves provide information about the structure of the earth? - Waves
S waves from quakes are not detected on the other side of the earth, implying that the outer core must be liquid. P waves are detected on the opposite side of the Earth. Rarefactions cause 2 zones with no P-waves. The position of these indicates a solid inner core
46
What is a lens? - Waves
A lens is a shaped piece of transparent glass or plastic that refracts light
47
What is a convex/concave lens? - Waves
Convex - a lens that is thicker in the middle than at the edges. Causes parallel rays to CONVERGE Concave - a lens that is thinner in the middle than at the edges. Causes parallel rays to DIVERGE
48
What is the principal focus? - Waves
Known as the ‘focal point'. The focus of a lens where light rays all converge or diverge to
49
What is the focal length? - Waves
The focal length is the distance from the lens to the principal focus
50
What 6 descriptions are there to describe an image formed by a lens? - Waves
Upright or inverted Magnified or diminished (bigger or smaller) Real or virtual (virtual image appears to come from behind the lens
51
How do you draw a ray diagram? - Waves
Draw a ray from object to lens parallel to principal axis. Once through lens ray should pass through principal focus. Draw another ray passing from object through centre of lens. Where they meet is the image
52
How can you calculate magnification? - Waves
Magnification = image height / object height | IMAGE HEIGHT AND OBJECT HEIGHT SHOULD BE GIVEN IN SAME UNITS
53
What happens to a surface when it absorbs a wave? - Waves
The energy of a wave is transferred to the particles in a surface which increases the internal energy of the particles
54
Why does grass appear green? - Waves
The grass absorbs the red, orange, yellow, blue, indigo and violet light, reflecting the green light which is what we see
55
What happens when waves are transmitted at a boundary between 2 materials? Give an example of waves being transferred - Waves
The wave continues through the material and then passes through. Air, glass and water are very good at transmitting light
56
When light passes through a colour filter, what happens? - Waves
All colours except for the wavelength of the colour of the filter is absorbed, with the colour of the filter being transmitted through the filter
57
What is a perfect black body? - Waves
A black body is a theoretical object which would absorb all radiation which falls on it and would not reflect or transmit any radiation
58
What is true of all objects that are good at absorbing energy (and therefore black bodies) - Waves
An object that is good at absorbing radiation is also a good emitter of radiation so a perfect black body would be a fantastic emitter of radiation
59
What is considered to be a black body in space? - Waves
Stars are considered to be black bodies because they are very good emitters of most wavelengths of the electromagnetic, suggesting they also absorb most wavelengths
60
What surfaces are the worst absorbers and emitters of visible light? - Waves
White and shiny surfaces are the worst absorbers as they reflect all visible light wavelengths
61
What does the Earth's temperature depend on? - Waves
The rate at which light and infrared radiation are absorbed by the Earth's surface and atmosphere and the rate at which they are emitted by the Earth's surface and atmosphere
62
What happens when the Earth's surface absorbs visible light and high frequency infrared radiation? - Waves
The internal energy of the Earth is absorbed and as a result the Earth's surface gets hotter
63
What can the Earth's surface also do as well as absorb infrared and light radiation? - Waves
The earth can radiate low frequency infrared radiation through the atmosphere and back into space or into the atmosphere where it is absorbed by greenhouse gases

Physics (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions