Unit 2.4: The Nature of Waves Flashcards
What is a Progressive wave?
A progressive wave is a pattern of disturbances travelling through a medium and carrying energy, involving the the particles of the medium oscillating about their equilibrium position.
The transfer of what is not involved with Progressive waves?
The transfer of matter.
There are 2 types of progressive waves, name them.
Longitudinal and transverse
What is a transverse wave?
The oscillations of the particles are at right angles to the direction of travel of the wave
Define a longitudinal wave.
The oscillations of the particles are in parallel with the direction of travel of the wave
Give one example of both progressive waves
Light(Transverse) and Sound(Longitudinal)
Define wavelength
The minimum distance between 2 points on the wave oscillating in phase
Define frequency
The number of cycles of a wave passing a given point every second
Define amplitude
Distance from the middle of the wave to the crest
Define speed of a wave
The distance travelled by the wave in 1 second
Define the term ‘Phase’
The relationship between the pattern of vibration of two points on a wave
What is Phase difference?
The difference in position of 2 points within a cycle of oscillation
Points which are oscillating in______ will be multiples of 360°
phase
Points which are oscillating in_____will be multiples of 180°
anti-phase
What is a polarised wave?
A polarised wave is a transverse wave in which particle oscillations occur in only one of the directions at right angles to the direction of wave propagation
Do domestic light bulbs and the sun emit
polarised or unpolarised light?
unpolarised
What is the difference between unpolarised light and polarised
With unpolarised ligtht the vibrations take place in many directions, instead of in the single plane associated with plane-polarised ratiation
What does a polaroid lens do?
A polaroid lens allows
oscillations in only one
direction to pass through,
the other directions are
absorbed.
What happens if you try to view plane polarised light through a second sheet of polaroid at right angles to each other?
If the polarised lenses are at right angles to each other,it will be found that the intesnity of light passing through will be 0.
