Chapter P12- Wave Properties Flashcards
What do waves transfer without transferring what?
What are the oscillations like in transverse waves?
What are the oscillations like in longitudinal waves?
What are oscillations?
What can transverse waves travel through?
What two things do transverse waves also contain?
What are examples of transverse waves?
What are peaks?
What are troughs?
Waves transfer energy without transferring matter
Perpendicular to the direction of travel
Parallel to the direction of travel
The vibrations of particles
A vacuum
Peaks and troughs
Visible light, radio waves, micro-waves and X-rays
The highest point of the wave
The lowest point of the wave.
What can’t longitudinal waves travel through?
What must longitudinal waves travel through?
What two things do longitudinal waves contain?
What are two examples of longitudinal waves?
What is a wavelength of a wave?
Where is the amplitude of a wave measured from?
What is one wavelength?
How can this be done?
What are two examples of doing this?
What is the amplitude of a wave?
What is this the height of?
A vacuum
A medium (eg air)
Compressions and rarefractions
Sound waves and earthquakes
One complete wave
The peak or the trough
The distance to complete one whole wave
By measuring from two identical points
Peak to peak or compression to compression
The maximum displacement from its undisturbed position
The peak or trough from the middle line.
What is the speed of a wave?
What is transferred by the wave at this speed?
What is the formula for the speed of a wave?
What is the speed of a wave measured in?
What is the speed of light (full and standard form)?
What is the speed of sound?
What is the frequency of a wave not?
What is the frequency of a wave?
What is frequency measured in?
What is the number of waves every second for 30 Hz?
What is the formula used to calculate the frequency of a wave?
The distance travelled by each wave every second through the medium
Energy
Speed= Distance -:- Time
m/s or ms to the power of -1
300,000,000 m/s or 3 x 10(power of)8 m/s
330 m/s (usually at sea level)
How quickly the wave is moving
A measurement of the number of waves passing through a fixed point every second
Hertz (Hz)
This means that the wave completes 30 waves every single second
Time Period= 1 -:- Frequency.
What is the formula for calculating wave speed (symbol and word)?
What is lamda?
What are the units for all of the parts of this equation?
What is each ripple called in reflection in a ripple tank and why?
What are the waves called when plane waves are directed at a metal barrier?
What is the refraction of waves?
What happens to plane waves directed at a non zero angle to the boundary?
What happens when plane waves cross a boundary at a non zero angle to the boundary?
What happens two things will happen when a wave is directed at a substance?
What two things is this dependant upon?
What happens to the waves go into a substance?
What would then happen to the substance and why?
What happens as waves travel through a substance and why?
Wave speed= Frequency x Wavelength (V= f x Lamda)
Wavelength
Wavelength= m
Wave speed= m/s
Frequency= Hz
A wavefront because it is the front of each wave as it travels across the water surface
Incident waves to distinguish them from the reflected waves
The change of the direction in which they are travelling when they cross a boundary between one medium and another medium
Change direction as they cross the boundary
Each wavefront experiences a change in speed and direction
Some or all of the wave may be reflected at the surface
The wavelength of the wave and also on the substance
Some or all of them may be absorbed by the substance
This would heat the substance because it would gain energy from the waves
The amplitude of the wave gradually decreases as the substance absorbs some of the waves energy.
What happens to waves that aren’t absorbed by the substance they are travelling through?
Why are plane waves reflected at the same angle to the barrier as the incident waves in a ripple tank?
When and when aren’t plane waves refracted?
What is the time period?
How can waves be generated on a string?
What does the angle of incidence equal in reflection?
What is refraction?
What does a vibrating object do to the air?
What two things does this send out in waves?
What do waves do when they reach the ears?
They are transmitted
Because their speed and wavelength do not change on reflection
When crossing a boundary between two different materials unless they cross the boundary at normal incidence
The time it takes for one wave to pass you
By attaching it to a vibrator (oscillator) and placing tension on it
The angle of reflection
Going from a less dense material into a more dense material the angle of refraction is smaller than the angle of incidence
Pushes and pulls repeatedly on the air
Compressions and rarefactions
They make the eardrums vibrate in and out so you hear sound.
How can you test that sound waves cannot travel through a vacuum?
What do sound waves reflect from?
Why is there a time delay in humans hearing an echo?
What is the formula for calculating speed of sound in air?
What experiments are used to investigate the following waves:
Water waves
Waves in a solid
Sound waves
What happens to sound waves entering a solid?
What only happens over a limited frequency?
What does this mean?
What two things happens to the frequency when sound waves travel from one substance to another?
What may then changes?
So, what happens to the frequency of the sound we listen to?
By listening to an electric bell in a ringing bell jar as the air is pumped out of the bell jar
Smooth and hard surfaces
Because the sound waves travel to the wall and back before you hear the echo
Speed= Distance to the wall and back -:- Time delay
A ripple tank
A stretched string
A signal generator and a loudspeaker
They are converted to vibrations that travel through the solid as vibrations
The conversion of sound waves to vibrations of solids
The frequency range of the human ear is limited
Their frequency doesn’t change but their speed may change depending on the two substances
Their wavelength may change
They do not change when the sound waves and vibrations pass through the air and the different parts of your ear.
When does the pitch of a note increase?
When does the loudness of a note increase?
What do sound waves cause the ear drum to do and what does this then do?
Where do earthquakes occur?
What is the focus?
What is the epicentre?
What are earthquakes recorded and detected by on the surface of the Earth?
What are primary waves also known as?
Describe primary waves?
What type of wave are primary waves?
What are secondary waves also known as?
Describe secondary waves?
What type of wave are secondary waves?
If the frequency of the sound waves increases
If the amplitude of the sound waves increases
Vibrate and the vibrations send signals to the brain
In the crust of the Earth
The point where the earthquake originates from
The closest place on the Earth’s surface to the focus
Seismometers
P-waves
They cause the initial tremors lasting about one minute
Longitudinal waves
S-waves
They cause more tremors a few minutes later and travel more slowly than p-waves
Transverse waves.
What are long waves also known as?
Describe long waves?
What are shadow zones?
Where is this zone from?
What has shadow zones told us about P-waves?
Why is this?
What has shadow zones told us about S-waves?
Why is this?
What are ultrasound waves?
Above what frequency are sound waves classified as ultrasound?
What are ultrasound waves used for?
What is an ultrasound scanner made up of and what is this called?
What two things does the transducer do?
L-waves
They arrive last and cause violent movements on the surface up and down as well as back and forth. They only occur in the crust
Where L-waves are detected by seismometers
105-142 degrees from the focus
They are refracted at the boundary between the mantel and the outer core
Because they travel at different speeds through liquids and solids
They can’t travel through the outer core as they are transverse waves
Because they can’t travel through liquids
Sound waves above the highest frequency that humans can detect
Above 20 kHz
Prenatal scans of a baby in the womb
An electronic device called a transducer
Produces and detects sets (or pulses) of ultrasound waves.
What is each ultrasound wave pulse from the transducer?
What does each ultrasound wave also do?
What type of radiation is ultrasound?
What is this?
What does this mean?
What is the formula for calculating the distance travelled by the wave?
What is the formula for calculating the depth of the boundary below the surface?
Partially reflected from the different tissue boundaries in its path
Returns to the transducer as a sequence of ultrasound waves reflected by the tissue boundaries, arriving back at different times
Non-ionising radiation
Radiation that doesn’t have enough energy to remove an electron to ionise an atom or molecule
Ultrasound waves are harmless when used for scanning
Distance= Speed of the ultrasound wave in body tissue x Time Taken
Depth= 1/2 x Speed of the ultrasound waves x Time Taken.
