Waves Flashcards
What do waves do?
Waves 🌊 transfer energy from one place to another.
What are the two types of waves 🌊?
Transverse and longitudinal
What does amplitude mean?
Height of the wave (middle to peak)
What is wavelength?
Length of one wave (distance between peaks)
What is frequency?
The number of complete waves passing a certain point per second. Measured in hertz (Hz)
What is the equation for wave speed?
Wave speed (m/s)= frequency (Hz) X wavelength (m)
What are transverse waves?
In transverse waves, the oscillations (vibrations) are perpendicular (at 90degrees) to the direction of energy transfer.
What are three examples of transverse waves?
1) all electromagnetic waves e.g. light
2) ripples and waves in water
3) a wave on a string
What are longitudinal waves?
In longitudinal waves, the oscillations are parallel to the direction of energy transfer.
What is an example of longitudinal waves?
Sound waves in air
How can you create water waves at a set frequency in the water ripples practical?
By using a signal generator attached to the dipper of a ripple tank
What is the strobe light used for in the water ripples practical?
To see wave crests on a screen below the tank.
Why is the strobe light a good piece of equipment?
It allows you to measure a still pattern instead of a constantly moving one.
What is the distance between each shadow equal to in the water ripples practical?
One wavelength
What do you do with the frequency of the strobe light in the water ripples practical?
Increase the frequency until one wave pattern on the screen appears to ‘freeze’ and stop moving. This happens when the frequency of the strobe light is equal to the frequency of the waves.
How far do you need to adjust the signal generator in the waves on strings practical?
Until there’s a clear wave on the string. The frequency you will need will depend on the length of string between the pulley and the transducer and the masses you’ve used.
How do you know what the frequency of a wave is?
The frequency of a wave is whatever the signal generator is set to (or you could measure it with a strobe in the ripple water practical).
Which wave has compressions and rarefaction?
Longitudinal
Which wave has trough, amplitude and peak?
Transverse
