P5 Flashcards
What is amplitude ?
Amplitude is the displacement from the rest position to the Crest/trough perceived as sound volume
What is wavelength?
Wavelength is the length of the full cycle from Crest to Crest/compression to compression
What is frequency?
Frequency is the number of complete waves/cycles passing point per second measured in hertz (Hz)
What is the period?
The period is the number of seconds it takes for one full cycle which is one divided by frequency
Definition of a transverse wave
transverse wave is a wave that the vibrations are perpendicular to the direction waves travel
Give three examples of transverse waves
EM waves, s waves, ripples
Definition of a longitudinal wave
A longitudinal wave has vibrations which are parallel to the direction of waves travel they are made up of compressions (high-pressure) and rarefractions (low-pressure)
Give two examples of longitudinal waves
Soundwave and P-waves
Wave speed =
Frequency X Wavelength
Describing experiment to find the frequency of a wave
1) Place a piece Whitepaper with a pencil line across it under ripple tank .
2) Turn it on and film the shadows on the paper for 10 seconds.
3) Slow mo the footage and count the number of ways.
4) Divide by 10 to find the frequency.
Describing experiment to find the wavelength of a wave
1) Put a piece of white paper with a ruler on it under a ripple tank .
2) Turn it on and take a picture.
3) Measure the distance between the first five waves and divide by 5 to get the wavelength
Describe an experiment to find the wave speed of a wave
1) Place a piece of white paper with a ruler along one edge under ripple tank .
2) Turn it on and take a picture.
3) Measure the distance between the first Five waves and divide by 5 to get the wavelength.
4) Then remove the ruler and draw a pencil line across the piece of paper film the shadows on the paper for 10 seconds.
5) slow mo the footage and count the waves.
6) Divide by 10 to find the frequency.
7) Then use the equation wave speed =frequency X wavelength .
Which three things can happen when wave meets a boundary?
1) Absorption – the energy is transferred into the second materials energy store
2) transmission – can travel through the new material (often refracted)
3) reflection
Angle of incidence=
Angle of incidence=angle of reflection
What is white light ?
Why it like it is a mixture of different colours of light with different wavelengths
Definition of specular reflection
Specular reflection is when all rays are reflected in a single direction by smooth surface producing a clear reflection
Definition of scattered reflection
scattered reflection is when rays are reflected in all different directions to different normals which doesn’t produce a clear reflection
Describe practical to investigate reflection
1) Draw a line across the piece of paper and place a plane mirror so it lines up with the solid line.
2) Draw dotted line (the normal) at 90° to the solid line
3) Use a ray box to shine a beam of light where the normal hits the mirror.
4) Trace the incidence and reflected ray
5) Measure the incidence and reflected angles you will find that they are equal
Definition of refraction
Refraction is the change of direction of a wave due to a change in speed when moving from one medium to another
What changes when a wave refracts and why
The wavelength of a wave changes when it refracts because the frequency never changes and as the wave speed changes and wave speed is equal to frequency times wavelength thus the wavelength must change
Do EM waves speed up or slow down when travelling into a more dense material ?
EM waves slow down when they travel into more dense materials
Do you soundwave speed up or slow down when travelling into more dense materials ?
Soundwave speed up when travelling into more dense materials
If a wave speeds up does it bend towards or away from the normal
When a wave speeds up it will bend away from the normal
If a wave slows down will it bend away from or towards the normal?
If a wave slows down it will bend towards st he normal
Which colours refractive the most and why
Violet retracts the most because it has the shortest wavelength
Describe an experiment to investigate the refraction of light
1) place a glass prism on a sheet of white paper
2) using a ray box and a coloured filter to shine a beam of coloured light at the prism
3) trace the incidence Ray and merging ray and label the colour
4) repeat using different coloured filters and you will find violet retracts the most and red retracts the least
What happens when white light is shone through a triangular prism?
The white light splits into the different colours of light because they all refract by different amounts