P12 Wave properties AQA
4.5 / 5 based on 5 ratings
- Created by: wolf.dz7
- Created on: 21-01-18 19:46
What are waves? [4 marks]
Waves are used to transfer energy and information, and not matter. Particles in the wave oscillate (vibrate) to and fro about a point. It is the whole wave that moves, and the particles don't travel themselves.
1 of 60
Choose the appropriate word: the direction in which a wave travels is _the direction/perpendicular to the direction_ in which the wave transfers energy. [1 mark]
the direction
2 of 60
What is a transverse wave? [2 marks]
A wave where the direction of vibration of the particles is perpendicular to the direction in which the wave travels, for instance, water waves.
3 of 60
What is a longitudinal wave? [2 marks]
A wave where the direction of vibration of the particles is parallel to the direction in which the wave travels, for instance, sound waves.
4 of 60
Longitudinal waves are made up of two things: what are they? [2 marks]
Compressions and rarefactions.
5 of 60
How would you describe a compression? [2 marks]
A compression is a region in a longitudinal wave where the particles are closest together.
6 of 60
How would you describe rarefactions? [2 marks]
A rarefaction is a region in a longitudinal wave where the particles are furthest apart.
7 of 60
What is a mechanical wave? [3 marks]
A wave that can only travel through a medium (substance) and requires particles to move, for instance, sound waves. Mechanical waves may be transverse or longitudinal.
8 of 60
What is an electromagnetic wave? [3 marks]
A wave that is able to travel through a vacuum, for instance, light waves and radio waves. All electromagnetic waves are transverse waves.
9 of 60
What is amplitude? [2 marks]
The amplitude of a wave is the height of the wave crest (top of the wave), or the depth of the wave trough (bottom of the wave), from the midpoint of the wave - or more simply, the wave's length vertically either up or down form the midpoint.
10 of 60
Choose the appropriate word: the greater the amplitude of the wave, the _more/less_ energy it carries. [1 mark]
more
11 of 60
What is wavelength (λ)? [1 mark]
The wavelength of a wave is the distance from one crest to the next crest or from one trough to the next trough.
12 of 60
What is frequency (f)? [1 mark]
The frequency of a wave is the number of wave crests passing a point in one second.
13 of 60
What are the units of frequency? [1 mark]
Hertz, Hz (which is equivalent to 'waves per second')
14 of 60
What is the period of a wave? [1 mark]
The period of a wave is the time it takes for one wavelength pass a point.
15 of 60
How can you work out the period of a wave? [1 mark]
period of a wave = 1 / frequency (f)
16 of 60
How can you work out the speed of a wave? [1 mark]
v = fλ (where v is the wave speed in m/s, f is the frequency in Hz, and λ is the wavelength in m)
17 of 60
In reflection and refraction, what are waves called that are travelling towards a barrier or boundary? [1 mark]
Incident waves
18 of 60
In reflection, what are waves called that are travelling away from a barrier or boundary after reflecting off it? [1 mark]
Reflection waves
19 of 60
In refraction, what are waves called that are travelling away from a barrier or boundary after crossing it? [1 mark]
Refraction waves
20 of 60
What happens in reflection? [3 marks]
The wave hits the barrier and the reflected wavefront moves away from the barrier at the same angle to the barrier as the incident wavefront.
21 of 60
In reflection, do the reflected waves have any change in speed or wavelength? [1 mark]
No
22 of 60
What happens in refraction? [2 marks]
The wave passes through the barrier into a transparent or translucent substance such as glass or water and the wave changes in speed. This change in speed causes a change in direction.
23 of 60
In refraction, do the refracted waves have any change in speed or wavelength? [1 mark]
Yes
24 of 60
When waves meet a boundary with a different substance they may be: [3 marks]
Totally or partially reflected; transmitted through the substance; absorbed by the substance.
25 of 60
Why are sound waves caused? [2 marks]
Sound is caused due to mechanical vibrations in a substance, and travel as a wave.
26 of 60
Are sound waves transverse or longitudinal? [1 mark]
Longitudinal - the direction of the vibrations is parallel to the direction in which the wave travels.
27 of 60
Are sound waves mechanical or electromagnetic? [1 mark]
Mechanical - they cannot travel through a vacuum and need a medium to travel.
28 of 60
How are echoes produced? [1 mark]
They are produced when sound waves are reflected off hard, flat surfaces such as walls.
29 of 60
How can we investigate waves? [3 marks]
By using: a ripple tank for water waves; a stretched string for waves in a solid; a signal generator and loudspeaker for sound waves.
30 of 60
How can you investigate waves on a string using a frequency generator and oscillator? (part 1) [8 marks]
Adjust the frequency of the oscillator until the string has a single loop. Note the frequency of the oscillator. Measure the length (L) of the loop and calculate the wavelength (λ) of the wave. For a single loop, λ = 2L.
31 of 60
How can you investigate waves on a string using a frequency generator and oscillator? (part 2) [8 marks]
Calculate the speed (v) of the waves on the string using v = fλ. Change the frequency of the oscillator to obtain more loops on the string. Calculate further values of λ and v to compare the wave speed.
32 of 60
How can you investigate water waves using a ripple tank? (part 1) [6 marks]
Create plane waves using a ruler. Measure the time taken (t) for a wave to travel from one end of the tank to the other. Measure the distance travelled (s). Calculate the speed of the water waves using v = s/t.
33 of 60
How can you investigate water waves using a ripple tank? (part 2) [6 marks]
Change the frequency of the waves by moving the ruler up and down faster. Calculate further values of v to compare the wave speed.
34 of 60
How can you investigate sound waves using a signal generator and loudspeaker? [5 marks]
Observe the loudspeaker cone vibrate when connected to the signal generator. Adjust the oscillator's frequency & see its effects on the loudspeaker cone's movement. Adjust the loudspeaker's volume & see its effects on the loudspeaker cone's movement.
35 of 60
Choose the appropriate word: the pitch of a note depends on the _frequency/amplitude_ of the sound waves. [1 mark]
frequency
36 of 60
Choose the appropriate word: the higher the frequency of the waves, the _higher/lower_ the pitch of the sound. [1 mark]
higher
37 of 60
Choose the appropriate word: the volume of a sound depends on the _frequency/amplitude_ of the sound waves. [1 mark]
amplitude
38 of 60
Choose the appropriate words: the greater the amplitude, the _less/more_ energy the wave carries and the _quieter/louder_ the sound. [2 marks]
more, louder
39 of 60
How do people hear sound (in terms of waves)? [3 marks]
Sound waves travel through the air. When they reach the ear, they make the eardrum vibrate. This sends an electrical signal to the brain.
40 of 60
What is the range of frequencies that the human ear can hear? [2 marks]
Between 20 Hz and 20,000 Hz
41 of 60
Choose the appropriate word: the ability to hear _higher/medium/lower_ frequencies declines with age. [1 mark]
higher
42 of 60
What are ultrasound waves? [1 mark]
Sound waves with a frequency higher than 20,000 Hz (too high for a human to be able to hear)
43 of 60
How can you scan using ultrasound? (part 1) [5 marks]
An ultrasound scanner uses an electronic scanner called a transducer to produce ultrasound waves. When a wave meets a boundary between two different materials, part of the wave is reflected.
44 of 60
How can you scan using ultrasound? (part 2) [5 marks]
The wave travels back through the material to be detected by the transducer. The time it takes to reach the transducer can be used to calculate how far away the boundary is. The results are processed by a computer to give an image.
45 of 60
How can you calculate the distance travelled by an ultrasound pulse? [1 mark]
s = vt, where s = distance travelled (m); v = speed of ultrasound wave (m/s); t = time taken (s)
46 of 60
Choose the appropriate word: the depth of the boundary below the surface is _equal to/half/double_ the distance travelled by the ultrasound pulse. [1 mark]
half
47 of 60
Name three uses for ultrasound. [3 marks]
It can be used in medicine for scanning soft tissue such as the eye and the kidney. Also, it can be used for scanning unborn babies. It can also be used in industrial imaging (for instance, for detecting flaws in metal casting)
48 of 60
Why is ultrasound safer than X-ray in medicine? [1 mark]
Ultrasound is non-ionising.
49 of 60
Where are earthquakes generated? [1 mark]
In the Earth's crust
50 of 60
What is the name of the point that the earthquake originates from? [1 mark]
The focus
51 of 60
What is the name of the closest point on the Earth's surface to the focus? [1 mark]
The epicentre
52 of 60
What type of waves do an earthquake produce? [1 mark]
Seismic waves
53 of 60
What direction do the seismic waves from an earthquake travel in? [1 mark]
They spread out from the epicentre in every direction.
54 of 60
What are primary seismic waves (P-waves)? [2 marks]
Longitudinal waves that cause the initial tremors in an earthquake.
55 of 60
What are secondary seismic waves (S-waves)? [2 marks]
Transverse waves which travel more slowly than P-waves and cause tremors that are produced after the first minute or so.
56 of 60
What are long waves (L-waves)? [3 marks]
Waves that only travel in the Earth's crust and while they are slower than P-waves and S-waves they cause violent movement in the Earth's crust.
57 of 60
Describe the transitions of P-waves and S-waves between the mantle and the core of the Earth. [3 marks]
P-waves refract at the boundary between the mantle and the core, whilst S-waves cannot travel through the core.
58 of 60
How is earthquake activity recorded and used? [2 marks]
It is recorded by detectors on the surface called seismometers. Seismometer readings from different parts of the world are used to determine where the epicentre of an earthquake is.
59 of 60
How has analysis of seismic waves help scientists? [4 marks]
It has allowed them to understand the structure of the Earth: there is a liquid inner core; a solid outer core that surrounds it; this is surrounded by the mantle; and there is a 50km deep crust around the mantle.
60 of 60
Other cards in this set
Card 2
Front
Choose the appropriate word: the direction in which a wave travels is _the direction/perpendicular to the direction_ in which the wave transfers energy. [1 mark]
Back
the direction
Card 3
Front
What is a transverse wave? [2 marks]
Back
Card 4
Front
What is a longitudinal wave? [2 marks]
Back
Card 5
Front
Longitudinal waves are made up of two things: what are they? [2 marks]
Back
Related discussions on The Student Room
Similar Physics resources:
0.0 / 5
0.0 / 5
0.0 / 5
5.0 / 5 based on 1 rating
Teacher recommended
0.0 / 5
4.5 / 5 based on 3 ratings
0.0 / 5
4.5 / 5 based on 4 ratings
4.0 / 5 based on 3 ratings
0.0 / 5
Comments
No comments have yet been made