What is a characteristic of a longitudinal wave?
The particle vibrations are parallel to the directionof travel.
How is a stationary wave formed ?
- include five points -
A stationary wave is formed when two progressive (1) waves traveling in opposite directions (2) and of the same wavelength (3) meet and interfere (4).
This interference can either be constructive or destructive (5).
a) The process by which only one plane of waves is allowed through a filter is called what?
b) And with which type of waves does this occur?
b) Transverse waves
Draw a stationary wave clearly labeling and nodes and antinodes.
Ensure that any nodes are at equilbrium and any antinodes are at points of maxium displacement.
State a charactersitic of a stationary wave.
Stationary waves do not transfer energy.
State one characteristic of a progressive wave.
Progressive waves do transfer energy.
What is a characteristic of a transverse wave ?
And give two examples of transverse wave.
The particle vibrations are perpendicular to the direction travel.
e.g Water, light.
What is the objective of a progressive wave?
To transfer energy and not matter.
On a diagram of a wave what represented by the:
a) X axis
b) Y axis
What is meant by the 'Time Period' ?
The time taken for one oscillation.
Frequency = 1/?
Wave speed =
Wave length x frequency
What does the Refractive Index tell us?
The degree by which a material can decrease the speed of light.
If a ray of light travels through a material with refractive index 1.26 to a material with refractive index 1.13 will the light slow down or speed up?
What does this tell us in relation to the two materials?
The ray of light will speed up.
This tells us that the first material is more dense than the second.
A ray of light leaves an optically denser material than that of which enters.
Does it refractive towards or away from the normal?
It refracts away from the normal.
By which process do optical fibres operate ?
Total Internal Refection
If two waves in the same phase meet what happens?
They interfere constructively
2π radians is the same as ...
360º or 1 wavelength
π / 2 radians is the same as ...
90º or 1/4 wavelength
What is happening in the fundamental frequency ?
The wave is vibrating at the lowest possible resonant frequency. This is equivalent to half a wavelength fitting on the object that is vibrating.
By observing d, theta and n through a diffraction grating you can calculate the wavelength.
What do do they stand for?
d is the diffraction grating spacing
theta is the angle from the light source that the light hits the screen at.
n is the order of diffraction, zero is the central maxima, 1 is the first one out from the centre, 2 is the second one out etc.