Flashcards in Waves Deck (184)
What is a progressive wave?
Vibrations through the air that carries energy from one place to another without transferring any material
How is a wave produced?
Caused by something making particles or fields oscillate at a source
What happens to the energy at the source of a wave?
It decreases as the wave transfers energy away from the source
What is reflection?
When a wave bounces back when it hits a boundary
What is refraction?
When a wave changes direction as it enters a different medium
Why does a wave change direction (refracts) when it enters a different medium?
Because the wave speeds up or slows down
What is diffraction?
When a wave spreads out as it passes through a gap or round an obstacle
What is the displacement of a wave?
How far a point on the wave has moved from it's undisturbed position
What is the SI units of the displacement of a wave?
What is the amplitude of a wave?
The maximum displacement of a wave (e.g. distance from undisturbed position to peak or trough)
What is the SI units of the amplitude of a wave?
What is the wavelength of a wave?
The length of one whole wave cycle (e.g. distance from peak to peak or trough to trough)
What is the period of a wave?
The time taken for one whole wave cycle
What is the SI units of the wavelength of a wave?
What is the SI units of the period of a wave?
What is the frequency of a wave?
The number of whole wave cycles per second passing a given point
What is the SI units of the frequency of a wave?
What is the phase of a wave?
A measurement of the position of a certain point along the wave cycle
What is the phase difference of a wave?
The amount by which one wave is behind another
What is the phase and phase difference of a wave measured in?
Degrees or radians as an angle or in fractions of a cycle
How do you work out the phase difference of 2 different waves?
Work out the difference between 2 identical points on each wave (e.g. the peak of both waves)
What equation links frequency and time period?
F = 1 / T
What is the wave speed?
The speed that a wave travels at
What is the equation for wave speed?
Wave speed = Frequency x Wavelength
What speed do all electromagnetic waves travel at through a vacuum?
What is a transverse wave?
A wave where the oscillations are at right angle to the direction of energy propagation
Are EM waves transverse or longitudinal?
How do transverse waves travel?
As vibrations through magnetic and electric fields
What are 3 examples (except EM waves) of a transverse wave?
Waves on a string
Waves on water