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

What is a mechanical wave?

A

A wave that travels through a substance / medium

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

What is an electromagnetic wave?

A

A wave that travels through a vacuum

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

What are some examples of mechanical waves?

A

Sound waves, water waves and seismic waves

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

What are some examples of electromagnetic waves?

A

Light waves, radio waves and microwaves

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

What is the direction of oscillation in a longitudinal wave?

A

Parallel to the direction of energy transfer

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

What is the direction of oscillation in a transverse wave?

A

Perpendicular to the direction of energy transfer

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

What is the time period of a wave?

A

The time it takes for one complete oscillation to occur

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

What is refraction?

A

The bending of waves when they move from one medium (substance) into another

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

Why does refraction happen?

A

Because the waves change speed when they move from one medium to another
(Light moves slowly in more dense media e.g. water)

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

What is the process of the refraction of a light ray going through air and then water?

A

As the ray of light enters the water, it slows down because water is more dense than air. This causes the ray to change direction
As the ray of light leaves the water, it speeds up again because air is less dense than water and this causes the ray to change direction again

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

What is the law of reflection?

A

That 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
12
Q

How would an image in a mirror be described?

A

Upright
Same size as object
Distance from mirror to object = ‘distance’ from image to mirror
Laterally inverted
Virtual

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

What does it mean when an image is described as virtual?

A

The light rays never really go there - our brains just think they do (like in a mirror)

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

What happens when wave fronts are reflected at a boundary?

A

There is no change in speed, wavelength or frequency and the law of reflection is obeyed

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

What happens when wave fronts are refracted at a boundary?

A

The speed and wavelength decreases but the frequency stays the same

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

What colour is low frequency light?

A

Red

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

What colour is high frequency light?

A

Violet

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

What is dispersion?

A

The separation of frequencies by refraction

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

What are the primary colours in light?

A

Red, blue and green

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

What are the secondary colours in light?

A

Yellow, cyan and magenta

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

What does it mean if an image is described as magnified?

A

That the image is larger than the object

22
Q

What does it mean if an image is described as diminished?

A

That the image is smaller than the object

23
Q

What does it mean if an image is described as upright?

A

That the image is the same way up as the object

24
Q

What does it mean if an image is described as inverted?

A

That the image is upside-down to the object

25
Q

What does it mean if an image is described as real?

A

That rays pass through the object

26
Q

How would an image through a concave lens be described?

A

Diminished, upright and virtual

27
Q

What is a black body?

A

A perfect black body is defined as something that absorbs all of the electromagnetic radiation that hits it and is the best possible emitter

28
Q

What is the closest thing we know to a perfect black body?

A

A star

29
Q

What does the range and wavelength of emitted radiation depend on?

A

Temperature (not the substance emitting it)

30
Q

How are earthquakes caused?

A

When the tectonic plates that make up the Earth’s crust move relative to one another

31
Q

Is a primary wave longitudinal or transverse?

A

Longitudinal

32
Q

Is a secondary wave longitudinal or transverse?

A

Transverse

33
Q

What are the properties of primary waves?

A

They cause the ground to move up and down
They can pass through solids and liquids
They travel faster through more dense materials

34
Q

What are the properties of secondary waves?

A

They cause the ground to move from left to right
They only pass through solids
They are slower than primary waves
They go faster through more dense materials

35
Q

What are the properties of sound waves?

A

Sound travels fastest through solids, then liquids, then gases
Sound waves will refract as they enter different materials
When sound enters a dense material, its speed will increase and the wavelength decreases

36
Q

How is the loudness of a sound wave shown?

A

By the height (half peak to peak) of the wave, called the amplitude

37
Q

How does wavelength affect pitch?

A

A shorter wavelength means a higher pitch and a longer wavelength means a lower pitch

38
Q

What are ultrasound waves?

A

Vibrations at a higher frequency than the human ear can detect

39
Q

What is the human hearing range?

A

20 - 20,000 Hz

40
Q

What are the uses of ultrasound?

A

Echo location in certain animals
Scanning babies in the womb
Cleaning delicate instruments and jewellery
Navigation underwater (sonar)
Finding and treating kidney stones
Purification of water

41
Q

What is the speed of sound in air and water?

A

330m/s in air and 1500m/s in water

42
Q

What are the advantages of ultrasound scans?

A

Non-invasive
Accurate
Considered risk free as it doesn’t damage body cells
Real time video

43
Q

What are the disadvantages of ultrasound scans?

A

Images from deeper in the body result in poorer resolution
Relies on the expertise of a sonographer
Before 18 weeks, pregnancy scans won’t show anything but major problems with the baby

44
Q

What are areas of compression in a wave?

A

Parts where the medium is squashed

45
Q

What are areas of rarefaction in a wave?

A

Parts where the medium is stretched

46
Q

What are the range of wavelengths in the EM spectrum?

A

From 10 to the power of -15 to 10 to the power of 4 metres

47
Q

How are EM waves produced?

A

By the acceleration of charged particles, for example
Electrons inside atoms
Protons moving inside an atomic nucleus
Electrons moving in an aerial

48
Q

How are radio waves produced?

A

1) An alternating current is fed into a transmitter
2) This causes electrons in the metal transmitter aerial to oscillate
3) This produces radio waves that cause electrons in the metal receiver aerial to oscillate
4) A matching alternating current comes out of the receiver

49
Q

What are some components of background radiation?

A

Radon gas, food and drink, cosmic rays, nuclear power and air travel

50
Q

What is the order of the EM spectrum?

A

Radio waves, microwaves, infrared radiation, visible light, ultraviolet light, x rays, gamma rays
The wavelength decreases as the list goes on but the frequency increases

51
Q

What is a use for each component of the EM spectrum?

A

Radio waves: communication and broadcasting
Microwaves: cooking food
Infrared: radiators and thermal imaging cameras
Visible light: things can be seen
Ultraviolet light: to purify water
X rays: to see broken bones
Gamma rays: in cancer treatments

52
Q

What are the dangers of electromagnetic radiation?

A

Ultraviolet radiation, x rays and gamma rays are all ionising radiations which is very dangerous as they can mutate cells and increase the likelihood of cancer

Physics (8 decks)

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