3-waves Flashcards
what is the unit.symbol for wavelength?
λ
what is a wavelength?
the diatance from one peak to the next
what is the symbol/definition for frequency?
how many (complete) waves there are per second (passing a certain point)
f
what is amplitude?
the height of a wave (rest (middle) to trough or rest to crest)
what is the speed of a wavelength?
the velocity of a wave aka the distance a wave travels in a given amount of time
what is the unit/symbol for speed?
m/s, v
unit for frequency?
Hz
what is period?
the time taken for one complete wave to pass a point.
what is the symbol for a period?
T
what is the equation linking frequency and period?
f = 1/t (1 being the number of waves)
what is the equation for wave speed?
wave speed = frequency x wavelength
or v = f x λ
what is the unit for wavelength?
m, metres
what is frequency?
How many waves pass a point in a second
What is a transverse wave (and an example)?
In a transverse wave the oscillations are perpendicular to the direction of energy transfer. The ripples on a water surface are an example of a transverse wave.
Sound waves are transverse
What is a longitudinal wave (and an example)?
In a longitudinal wave the oscillations are parallel to the direction of energy transfer.
E.g., sound waves, ultrasound waves
Explain the difference between Transverse vs Longitudinal waves
Both the transverse and longitudinal waves have different directions of oscillations. Transverse waves will have oscillations perpendicular to the direction of travel. Longitudinal waves will have oscillations parallel to the direction of travel, as shown in the diagram.
What is a wavefront?
when two or more waves move together, they have wavefronts.
wavefronts are imaginary planes that cut across all the waves, connecting the points on adjacent waves which are vibrating together.
the distance between each wavefront is equal to one wavelength i.e. each wavelength is at the same point in the cycle
( An imaginary surface representing points of a wave that are at the same point in their cycle.)
What do waves transfer?
Energy and information without transferring matter
Can all waves be refracted and reflected or not, including light waves?
Yes, they can
What is the law of reflection?
The normal is a line at right angles to the barrier. The angle of incidence i, is the angle between the direction of travel (the green line) for the incident waves and the normal.
The angle of reflection, I, is the angle between the direction of travel (the green line) for the reflected waves and the normal.
The angle of incidence always equals the angle of reflection.
What is the relationship between refractive index, angle of incidence, and angle of refraction?
N = refractive index
n = sin i / sin r
What is refraction?
Process by which a wave changes speed and sometimes direction upon entering a denser or less dense medium, eg a light ray changes direction when refracted by a lens. is the change in direction of a wave at such a boundary.
What is the relationship between the critical angle and the refractive index?
sin c = 1 / n
Can longitudinal waves be reflected and refracted?
yes