Remains unaltered
No, light in a medium will travel at a slower speed.
The speed of light is the speed at which electromagnetic waves propagate through a medium. The speed of sound is the speed at which acoustic waves propagate through a medium. As the speed of sound relies on the medium moreso than the speed of light, sound propagates much slower than light.
Refractive Index= Speed of Light in Vaccum / Speed of Light in the material
The refractive index is the ratio of the speed of light in a vacuum to the speed of light in a medium.
This is called the index of refraction. When light crosses the boundary between mediums (media) with different indices, it is bent (refracted).It's usually defined the other way around ... the ratio of the speed of light in vacuum to its speed in the medium. Since the speed of light is greater in vacuum than in any medium, the number is always greater than 1. It's referred to as the "refractive index" of the medium.
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.
When you change density and temperature you effect the way sound travels through a medium.
Speed of sound depends on the density of the medium. As temperature increases density decreases due to expansion in the volume. Hence speed of sound gets affected by the change in temperature. Speed of sound is directly proportional to the square root of the temperature of the medium.
floating
The speed of light is not medium: in vacuum, it is the highest speed that there can be. Hardly a definition of medium!
because the density of the medium changes with temprature
Yes. It depends on the refractive index of the medium through which the light is travelling.
Dependence of the speed of sound on the properties of the medium: The speed of sound is variable and depends mainly on the temperature and the properties of the substance through of which the wave is traveling. For example, in low molecular weight gases, such as helium, sound propagates faster compared to heavier gases, such as xenon. In a given ideal gas the sound speed depends only on its temperature. At a constant temperature, the ideal gas pressure has no effect on the speed of sound, because pressure and density (also proportional to pressure) have equal but opposite effects on the speed of sound, and the two contributions cancel out exactly. In non-ideal gases, such as a van der Waals gas, the proportionality is not exact, and there is a slight dependence on the gas pressure, even at a constant temperature. Humidity also has a small, but measurable effect on sound speed (increase of about 0.1% to 0.6%), because some oxygen and nitrogen molecules of the air are replaced by the lighter molecules of water. Cheers ebs
The speed of light depends on the refractive index (optical density) of the medium through which it travels. It is not affected by temperature.
No, light in a medium will travel at a slower speed.
c divided by the index of refraction of the medium = the speed of light in the medium.
No it is not true. When the temperature of the medium increases the speed of sound in that medium increases.