Waves Flashcards
(23 cards)
Name two types of wave.
Transverse and longitudinal.
What do waves transfer?
Energy but not matter.
What is the direction of oscillation in a transverse wave?
Perpendicular to the direction of energy transfer.
What is the direction of oscillation in a longitudinal wave?
Parallel to the the direction of energy transfer.
Can electromagnetic waves travel through a vacuum?
Yes.
What is the amplitude?
It is the maximum distance from the mean position.
What is the wavelength?
It is the distance for one complete oscillation.
What is the frequency?
It is the number of complete oscillations per second.
What is a ray?
A line drawn at right angles to the wavefront which shows which way the wave is travelling.
Wave equation:
Wave speed = frequency x wavelength
Another wave equation:
Frequency = wave speed / wavelength
Can all waves be reflected?
Yes.
What is the Law of Reflection?
The angle of incidence is equal to the angle of reflection.
What is the normal?
An imaginary line at 90 degrees to the surface.
What is constructive interference?
When crest meets crest creating a bigger wave.
What is destructive interference?
When a crest meets a trough and they cancel each other.
Describe the image in a plane mirror.
Upright
The same size as the object
Virtual (rays if light do not touch the image)
Laterally inverted (left and right are swapped)
What happens when light go into a less dense medium?
It speeds up.
What happens when light goes into a more dense medium?
It slows down.
What happens if the direction of travel of the light is not along the normal?
It bends - refracts.
What is diffraction?
It is when a wave passes a barrier or goes through it and spreads out.
What happens to the wavelength and frequency when a wave diffracts?
They stay the same - only the edges spread out.
What waves diffract more: longer or shorter waves?
Longer waves diffract more than shorter waves.
