Waves and Optics Flashcards
What is a longitudinal wave?
The vibrations or displacement are parallel to the direction of energy transfer.
What is a transverse wave?
A wave where the displacement or vibrations are perpendicular to the direction of energy transfer.
What is a progressive wave?
A progressive wave transfers energy without transferring material and is made up of particles oscillating.
What is the amplitude of the wave?
A wave’s maximum displacement from the equilibrium position (m)
What is frequency?
The number of complete oscillations passing through a point per second. (Hz)
What is the wavelength of a wave?
The distance between two particles in adjacent waves at the same phase of the wave cycle.
What is wave speed and how is it calculated?
v = fλ
What is a transverse wave?
A type of wave where energy moves perpendicular to the oscillations
What is the time period?
The time taken for one whole oscillation
What is constructive interference?
When 2 or more waves have displacement in the same direction
What is destructive interference?
When one wave has positive displacement and the other has negative displacement (if they are equal total destructive interference occurs)
What is a node (waves)?
Region of no displacement
What is an antinode?
Region of maximum displacement
What is the fundamental frequency?
The lowest frequency of a stationary wave that can be supported by a system
How do you determine the resultant displacement after interference?
The vector sum of displacements
What is a stationary wave?
A wave where energy is not transferred from one point to another, but oscillations still happen.
How far must two points be to support a stationary wave?
An integer number of half wave lengths
What are the two ways a stationary wave can be formed?
- 2 coherent progressive waves travelling in opposite directions.
- Reflecting a wave of a constant frequency and amplitude between two points.
What are coherent waves?
Waves of a fixed phase relationship and same frequency.
What is refraction?
Change in direction of waves as it travels through different media caused by the medium’s optical density.
What is the refractive index of air?
1
What is the refractive index of a material?
A measure of how fast light travels through it compared to the speed of light in a vacuum. (c/v)
What is the relationship between frequency and refraction?
The higher the frequency the larger the change in wavelength and speed.
What is the critical angle of incidence?
One where the angle of refraction is 90 degrees