3 Waves, Sound and EM Spectrum Flashcards
An ambulance is producing sound represented by wave 2
Which wave would represent the sound an observer would hear as the ambulance approached them?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/818/q_image_thumb.png?1514572404)
Wave 3.
The frequency of the sound would increase and wavelength decrease as the ambulance approached the observer.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/818/a_image_thumb.png?1514572669)
What is the use of UV radiation?
produced by tanning bed lights to tan skin
used to detect conterfeit money
used to clean water
Give three properties (features) common to all EM waves
They all…
travel at the speed of light
all transverse waves
all transfer energy and information without transferring matter
all travel through a vacuum
Which wave has the largest wavelength?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/821/q_image_thumb.png?1513899630)
wave 1
largest distance between adjacent crests
How can you make a transverse wave with a slinky?
Move your hand in a side to side movement
List the EM spectrum in order of decreasing frequency
Gamma
X-ray
UV
Visible
IR
Microwave
Radio
What is blueshift in terms of movement of stars or galaxies?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/824/q_image_thumb.jpg?1514623191)
If a star is moving towards the observer, the wavelength of the light it is producing is squashed.
The observer sees light of a smaller wavelength and higher frequency- it is a different colour as it is shifted towards the blue end of the spectrum
What is redshift in terms of movement of stars or galaxies?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/825/q_image_thumb.jpg?1514622905)
If a star is moving away from the observer, the wavelength of the light it is producing is stretched.
The observer sees light of a larger wavelength and lower frequency- it is a different colour as it is shifted towards the red end of the spectrum
How is wavespeed, wavelength and frequency related?
wavespeed = wavelength x frequency
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/827/a_image_thumb.jpg?1513899899)
Label the compressions, rarefactions and wavelength on the longitudinal wave below
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/828/q_image_thumb.png?1513899570)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/828/a_image_thumb.jpg?1513899582)
What is 204 nm in m?
204 x 10-9 m
What is the Doppler effect?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/830/q_image_thumb.png?1514566487)
When there is a change in frequency (wavelength) of sound (or light) an object is producing as a result of relative movement away or towards an observer.
How can you make a longitudinal wave with a slinky?
move your hand in a forwards and backwards movement
Sketch a graph of how frequency varies with time as an object approaches an observer, passes them and then travels away from them.
Higher than normal frequency as car approaches
Lower than normal frequency as car move away
Black horizontal line is the actual frequency of the sound
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/832/a_image_thumb.png?1581235328)
How would you measure the frequency of waves passing a jetty?
Time how long it take for 10 waves to pass the end of the jetty
frequency = 10 waves / time for 10 waves to pass
An ambulance is producing sound represented by wave 2
Which wave would represent the sound an observer would hear as the ambulance travelled away from them?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/834/q_image_thumb.png?1514572404)
Wave 1.
The frequency of the sound would decrease and wavelength increase as the ambulance moves away from the observer.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/834/a_image_thumb.png?1514572576)
Fred noticed that 10 waves passed a point in 5 seconds. What is the frequency of the wave?
frequency = 10 waves/ 5 s
= 2 Hz
What is 700 micrometres in metres?
700 x 10-6 m
What is a wavefront?
A wavefront connects all points on a wave which are moving in phase
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/867/a_image_thumb.jpg?1513901786)
Fred noticed that 10 waves passed a point in 5 seconds. What is the period of the wave?
Time period = 5 seconds / 10 waves
= 0.5 seconds for one wave to pass
Which wave has the largest amplitude?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/870/q_image_thumb.png?1513899667)
wave 2
It has the largest displacement from the equilibrium
What is the unit for time period?
seconds or s
What is the unit for amplitude?
metres (m) or decibels(dB)
What has a larger wavelength?
Infrared or gamma?
Infrared
Match the following terms with their definition
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/874/q_image_thumb.jpg?1513898953)
frequency- the number of waves going past in one second
wavelength- the length of one repeat of the wave pattern
wave speed- how far a wave travels in one second
Why are UV waves dangerous?
They can damage the retina and damage eye sight
They can cause skin cancer
What is the use of microwaves?
produced by microwaves to cook food
produced by mobile phones to communicate
Produced by satellites to send signals to satellite dishes
What is a transverse wave?
Where the oscillation is 90° to the direction of wave travel
How do the waves of red light differ from waves of violet light
ROY G BIV
Red light-larger wavelength and lowe frequency- it has less energy
Blue light- smaller wavlength and higher frequency- it has more energy
What are the uses of infrared radiation (IR)
emitted by ovens to cook food
emitted by radiators to heat houses
emitted by tv controllers to control t.v.
What is the relationship between wavelength and frequency of a wave?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/303/767/880/q_image_thumb.jpg?1513898820)
As wavelength increases, frequency decreases
They are inversely proportional
What is the use of X-rays?
Used to detect breaks in bones
used to detect crystal structure in salts