The speed of a mechanical wave depends on the mechanical properties of the medium.
When the mechanical properties of the medium change, the speed of the mechanical
wave changes as a result.
The speed of an electromagnetic wave depends on the electrical properties of the medium.
When the electrical properties of the medium change, the speed of the electromagnetic
wave changes as a result.
The medium through which it is propagating. For exampl if the sound waves are travelling in air they will move slower than those travelling through a wall speed of sound in solids > speed of sound in liquids > speed of sound in gases
speed
It is sound travelling through a dense medium, like iron, for example.
The change in speed causes the light to bend. If it is travelling from an optically dencer to an optically rarer medium the ray will bend away from the normal. But if it is travelling from an optically rarer to an optically denser medium then it will bend towards the normal.
Light bends because of the difference of speed in each medium.
Air is the medium (if you are talking about something travelling through it).
The medium through which it is propagating. For exampl if the sound waves are travelling in air they will move slower than those travelling through a wall speed of sound in solids > speed of sound in liquids > speed of sound in gases
Travelling through a medium that is optically less dense. Vacuum is best.
The change in speed causes the light to bend. If it is travelling from an optically dencer to an optically rarer medium the ray will bend away from the normal. But if it is travelling from an optically rarer to an optically denser medium then it will bend towards the normal.
Temperature and the medium in which it is travelling
When temperature rises, the density of the medium changes. Speed of light through a medium is inversely proportional to the density of medium. So when the temperature increases, the density decreases and the speed of light in that medium increases. Note that this is the indirect effect of temperature. If light is travelling through vaccuum , then the temperature will have no effect on the speed of light.
Yes. It depends on the refractive index of the medium through which the light is travelling.
speed
It is sound travelling through a dense medium, like iron, for example.
The change in speed causes the light to bend. If it is travelling from an optically dencer to an optically rarer medium the ray will bend away from the normal. But if it is travelling from an optically rarer to an optically denser medium then it will bend towards the normal.
The speed of light in a material medium is slower than the speed of light in a vacuum. This is a consequence of the electromagnetic wave interacting with the atoms and molecules in the medium, a process merits its own question.Of course, this assumes the medium is transparent for the wavelength of light travelling through it.Light waves slow down when they pass through a medium, eg glass or water
refrction