P6 - Waves Flashcards
What is a vaccum?
What is the speed of light in a vaccum?
An area with zero particles in it.
3x10^8
What happens to the refracted ray when it enters an optically denser block from air?
The refracted ray (light) bends (move) towards the normal.
What happens to a refracted ray when it goes from an optically denser block to air?
The refracted ray (light) will bend (move) away from the normal.
What happens to a wave during refraction?
- 4 points
- The wave speed will decrease
- The frequency will remain constant
- The wavelength will decrease
- Therefore the wave will change direction (and bend away from the normal).
What is the normal, when drawing a ray diagram?
The normal is a imaginary line (perpendicular - a straight line at 90 degrees) to the incoming ray where it hits the boundry
When the wave bends TOWARDS the normal, what happens to the speed of the wave?
When the wave bends towards the normal, the speed of the wave SLOWS down
When the wave bends AWAY from the normal, what happens to the speed of the wave?
When the wave bends AWAY from the normal, the speed of the wave will INCREASE
Describe Transverse waves
Give examples
Transverse waves oscillate perpendicular (at 90 degrees) to the direction of the energy transfer.
e.g Electromagnetic(light) waves, water waves
Describe Longitudinal waves
Give an example
Longitudinal waves oscillate parallel to the direction of the energy transfer.
e.g Sound waves
Define Wavelength
The distance from one point on a wave, to the same point on the next wave
Define Amplitude
The distance from the wave’s equilibrium to the crest/trough of the wave.
Define Frequency
The number of waves which pass a point per second.
Define Period
The time it takes one complete wave to pass a point.
Wave Speed Equation
Frequency x Wavelength
Period Equation
1 / frequency (Hz)