Waves 2 Flashcards
(115 cards)
2 types of wave
Transverse
longitudinal
1 example of longitudinal waves
Sound waves
All waves transfer…from one place to another
Energy
True or false, all waves require a medium to travel in e.g air/ a solid
False
All longitudinal waves require a medium to travel in
Only some transverse waves require a medium to travel in
Amplitude meaning
Maximum displacement of a point on a wave away from its undisturbed position
Amplitude is the ….of a point on a wave away from its…
Maximum displacement
Undisturbed position
Amplitude is the maximum displacement…….undisturbed position
of a point on a wave away from its
Wavelength is the distance from a point on one wave to the equivalent point on the…
Adjacent wave
Frequency meaning
Number of waves passing a point each second
50Hz means how many waves are passing a point each second
50 waves
If 20 waves pass a point each second what is the frequency
20Hz
As frequency is the number of waves passing a point each second
Period of a wave meaning
Time taken for wave to pass a point (in seconds)
Frequency vs period
Frequency is number of waves passing a point each second
Period is time taken for a wave to pass a point
Unit for period of a wave
Seconds
Wave speed meaning
Speed at which the wave moves through a medium/ speed at which energy is transferred through a medium
Wave speed is the speed at which a wave moves through a…./ the speed at which energy is transferred through a…
Medium
Describe Method to determine speed of sound waves in air
1) lay out 500m tape measure in straight line on ground in the open air
2) person A stands at 0m mark holding pair of cymbals, person B stands at the 500m mark with timer
3) person A starts timing when they see person B clash the cymbals together
4) person A stops timing as soon as they hear the sound of the cymbals
5) calculate speed of sound wave by doing distance (500m)/ time taken
Errors: different people have different reaction times (some people I’ll be able to start the timer quicker after seeing the cymbals clash together than others which will effect the time recorded)
It takes a fraction of a second between seeing the cymbals clash and starting the timer and between hearing the sound and stopping the timer (so the time won’t be fully accurate)
2 improvements:
Repeat investigation with lots of different people being in charge of the timer and calculate the mean time on the timers
Use longer distance between person A and person B to make the time between person A seeing the cymbals clash and hearing them longer so that the time is more accurate
For method to find speed of sound waves in air what are 2 sources of error
Different people have different reaction times so some people may take longer than others between seeing the cymbals clash together and stating the timer
It takes a fraction of a second between seeing the cymbals clash together and pressing the timer and hearing the cymbals and stopping the timer so that time recorded won’t be fully accurate
2 improvements to method of finding speed of sound waves in air
Repeat investigation at least 9 times with different people timing and calculate mean time
Increase distance between person A and person B
3 things that can happen to a wave when it meets a new medium
1) is transmitted
2) energy is absorbed
3) reflected
Which ray and angle comes first out of reflection and incident
First incident ray and angle of incidence
Second reflected ray and angle of reflection
Range of human hearing
20Hz
20,000Hz
Lowest frequency humans can hear
20Hz
Highest frequency humans can hear
20,000Hz