Section 3: Waves Flashcards
What is a progressive wave?
Carries energy from one place to another without transfering any material.
What causes a wave?
Somthing making particles or fields osscillate at a source.
What is reflection?
The wave is bounced back when it hits a boudary.
What is Refraction?
When the wave changes direction as it enters a different medium. The change in direction is a result of the wave slowing down or speeding up.
What is diffraction?
When a wave spreads out as it passes through a gap, or a round an obsicle.
What is displacment in terms of waves?
How far a point on the wave has moved from it’s undisturbed position.
What is amplitude?
The maximum magnitude of the displacement.
What is wavelength?
The length of one whole wave oscillation.
What is a period?
The time taken for one whole wave cycle.
What is the frequency?
The number of whole wave cycles per second passing a given point.
What is Phase?
A measurment of the position of a certain point along the wave cycle.
What is Phase difference?
The difference in phase between two points on a wave, radians
What is the speed of light in a vacume?
3 X 10^8 m/s
What is the speed of a sound wave?
Around 340 m/s
What is a polarised wave?
A wave that oscillates in one direction only.
What is the principle of superposition?
When two or more waves cross, the resultant displacment equals the vector sum of the individual displacements.
When does constructive interference occur?
When a trough meets another trough and peak meets peak.
When does deconstructive interference occur?
When a crest meets a trough.