The Nature of Waves (Unit 2) Flashcards
Does a progressive wave transfer energy?
transfers energy without any transfer of
matter
How many types of PROGRESSIVE WAVES are there?
2
- transverse
-longitudinal
What is special about TRANVERSE waves compared to longitudinal waves?
the oscillations of the particles are at right angles to the direction of travel of the wave
What is special about LONGITUDINAL waves compared to transverse waves?
the oscillations (of the particles) are parallel to the direction of travel of the wave
Examples of transverse waves?
Electromagnetic waves (light waves)
Examples of longitudinal waves?
Sound waves
What experiment do you do to measure intensity variations for polarisation?
A source of unpolarised light
-use 2 polaroid’s, and put them in front of each other, note the intensity and rotate 90 degrees and note intensity, rotate another 90 degrees and note intensity
How do you turn unpolarised light into the same plane of polarisation?
-Passing unpolarised light through a polariser (filter) allows though light with the same plane of polarisation.
What is polarisation?
the process of turning an unpolarised wave , into a PLANE POLARISED WAVE , it requires a polariser
What happens if during the experiment there is maximum brightness?
The polaroid sheets are lined up parallel.
What happens if during the experiment there is 0 light?
When the polaroid sheets are lined up perpendicular to one another.
What is meant by in phase?
Waves are said to be in phase if they have the same frequency and are at the same point in their cycles at the same time.
What is meant by in anti phase?
If two points are at opposite points in their cycle at the same time
What do we need to know about wavefronts?
-all points on a wave front oscillate in phase
-the wave fronts are at right angles to the direction of propagation of the waves.
What is meant by displacement?
The distance of a particle from its equilibrium position at any instant
