Wave Motion and Superposition Flashcards
What is coherence?
Waves or sources with constant phase difference
Explain how the stationary is formed on a stretched string?
Waves are reflected at the pulley end (where it is attached to). This produces nodes and antinodes on the string.
State the principle of superposition of waves
(When two or more waves meet at a point in space) the resultant (displacement) is equal to the (vector) sum of the individual displacements of waves (meeting at a point)
What is amplitude?
The maximum distance moved from the rest point.
What is displacement?
The distance moved, in a particular direction, from the rest point by an oscillating particle.
What is wavelength?
The length for one complete cycle.
What is period?
The time taken for one complete cycle.
What is frequency?
The number of cycles per unit time.
What is intensity?
The power per unit cross-sectional area.
What is a longitudinal wave?
A wave where the oscillations of the particles or field are parallel to the direction of motion of the wave.
What is a transverse wave?
A wave where the oscillations of the particles or field are perpendicular to the direction of motion of the wave.
What is a progressive wave?
A wave which transfers energy or information through the medium as a result of the oscillations of particles
or a field.
What is a standing wave?
A wave which does not transfer energy or information through the medium as a result of the oscillations of
particles or a field.
What is phase difference?
The amount by which two waves are out of step with each other.
What is path difference?
The difference in distance travelled for two waves coming from different sources but reaching the same point.
What is wave speed?
The distance travelled by a wave per unit time. Given by the product of the wavelength and frequency of a
wave.
What is interference?
When two or more coherent waves of the same type overlap and their displacements sum together, changing the
overall intensity.
What is constructive interference?
Waves have a phase difference of 0° so that the interference produces a maximum possible displacement.
What is destructive interference?
Waves have a phase difference of 180° so that the interference produces a minimum possible displacement.
What is a node?
The point on a standing wave, created by destructive interference such that there is no movement.
What is an antinode?
The point on a standing wave, created by constructive interference such that there is maximum movement.
What is the fundamental mode of vibration?
The standing wave of largest wavelength that can exist.
What is the fundamental wavelength?
The highest wavelength of standing wave that can exist in a system.
What is the fundamental frequency?
The lowest frequency of standing wave that can exist in a system.
What is a harmonic?
A standing wave which has a frequency which is a multiple of the fundamental frequency.
What is the refractive index?
(Speed of light in a vacuum)/(Speed of light in that material)
What is a plane polarised wave?
A transverse wave whose oscillations in one direction are confined to a single plane.
