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The speed of light (c) in a vacuum, is exactly299,792,458 meters per second (ms-1), which rounds up very nicely to 300,000,000 ms-1, which scientists write as 3 x 108 ms-1.
In more dense media the speed is slower,
e.g. # Air, only slightly less than c, speed is 0.9997 of c. # water 0.75 of c. # fused quartz 0.686 of c. # crown glass* 0.658 of c. # dense flint glass* 0.60 of c. # diamond, approx 0.41 of c. CALCULATIONS The speed of light, using a very close approximation for calculation purposes, is taken as 3.0 x 108 m/s (metres per second). i.e. 300,000,000 m/s The greater the refractive index of the medium, the slower the speed of light in that medium/material. The speed of light in a vacuum [c] divided by the velocity of light in the material [v] equals the refractive index [n] of the material. Examples 1. calculate the refractive index of space: c/c equals 1 2. water (the speed of light in water is 225,056,264 m/s): c/ 225056264 equals 1.333 Inversely, if we know the refractive index of a material, we can calculate the velocity of light through that material, i.e. the speed of light [c] divided by the refractive index [n] equals the velocity of light [v] in that material Using the example of water, refractive index 1.333 :- 300,000,000 [c] divided by 1.333 [n] equals 225,056,264 [n] i.e. the velocity of light in water is 225,056,264 m/s. This is 225,056,264/300,000,000 ths the speed of light, or 0.75 of c. SOME REFRACTIVE INDICES * vacuum1.00 * air 1.0003 * water 1.333 * fused quartz 1.4585 * plexiglass 1.51 * crown glass* 1.52 * diamond 2.417 * gallium phosphide 3.50 *Crown glass is a type of glass used in lenses, and has a lower refractive index than flint glass which is also used in lenses. For more information, see Related Links below this box
Wiki User
∙ 8y ago
Wiki User
∙ 13y agono, the speed of light in a material is always less than c because the photons are continuously being absorbed and reemitted by the material. this process takes time and slows down the light rays. the refractive index measures how much less.
Wiki User
∙ 14y agoThe speed of light is only constant in a vacuum. It changes for different materials.
Light's speed in vacuum is 300 000 000 m\s.
3 x 108 m\s in air,
2.26 x 108 m\s in water
and 1.97 x 108 m\s in glass.
Wiki User
∙ 13y agoIt depends on refractive index which is =( sine of angle of incidence)/(sine of angle of refraction)
And angle of refraction depends on type of material, so in a way YES, it depends on type of material.
The speed of light is only several m/s in supercooled liquid helium.
Wiki User
∙ 14y agoNo, in most media it is less than the speed of light in a vacuum. Some cases have been found where the speed of light in certain media is MORE than the speed of light in a vacuum; but apparently there is reason to believe that this can't be used to transfer information faster than the speed of light; in other words, somehow this is an apparent velocity. Materials with a negative velocity have also been found - the light gets out of the material before it comes in. Again, this seems to be only an apparent speed, not usable for transferring information to the past.
Wiki User
∙ 10y ago- space, the speed of light is c or exactly 299792458 m/s
- water, the speed of light is 0.769c or 230540400 m/s
- diamond, the speed of light is 0.417c or 125013455 m/s
Wiki User
∙ 15y agoThe speed of light is 2,99,7,92,458 meters per second or approximately 3x108 m/s
Wiki User
∙ 12y ago299,792,458 meters per second
186,282 miles per second
Usually designated as ' C ' in Physics formulas.
Wiki User
∙ 12y agoThe speed is constant while it's in the material. It changes
at the boundary between one material and another one.
Wiki User
∙ 12y agoThe speed of light through different media is equal to
Speed of light in vacuum/Refractive index of the medium .Add your answer:
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When will an eletromagnetic wave travel slower than the speed of light?
Light is an electromagnetic wave.All types of electromagnetic wave travel at the same speed,as long as they're traveling through the same stuff.The speed is 299,792,458 meters per second in vacuum, andsomewhat slower in any material. The exact speed dependson the material, and it's different for every material.
Optical density formula?
Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.
What is the formula for the speed of light and which light between gamma rays and radio have the highest speed?
The formula for the speed of light, in vacuum, isc = 299,792,458 meters/second . where ' c ' is the speed of light.In any material substance, the speed of light isc/(the index of refraction for that substance) . Gamma rays, radio waves, and all other members of the electromagnetic spectrumbetween those, all have the same speed.
What is affects the speed of a light wave?
Light changes speed when it passes through a transparent substance, based on the refractive index. For diamond, the dense crystal slows light to less than half of its velocity as measured in a vacuum.
Why wavelenth changes with speed of light?
Wavelength does not change with the speed of light, nor does the speed of light change for different wave lengths. Wavelength x frequency = c (the speed of light) always for any given medium through which it travels. Greater wavelength yields lower frequency, so the speed is always the same. Speed changes as light passes into different media transparent to light, but the change in speed has nothing to do with any change in frequency or wavelength. Those are related only to the nature of the material and the particular light energies it may pass or absorb. So white light passing through a red filter emerges red because the blue and green frequencies have been absorbed by the filtering material. That change in wavelength and frequency is not related to any change in speed within the filter.
Which is a comparison of the speed of light in a material compared to the speed of light in empty space?
The speed of light in any material medium is less than it is in empty space.
When will an eletromagnetic wave travel slower than the speed of light?
Light is an electromagnetic wave.All types of electromagnetic wave travel at the same speed,as long as they're traveling through the same stuff.The speed is 299,792,458 meters per second in vacuum, andsomewhat slower in any material. The exact speed dependson the material, and it's different for every material.
Which light has the ACCURATE speed?
ANY light traveling through the same medium (stuff) has the same speed.
Any vehicle speed is same as light speed?
No. Not even one thousandth of the speed of light.
Optical density formula?
Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.Optical density is the same in SI as in other system of units, since it is a dimensionless number. It is called the index of refraction, and can be defined as the speed of light in a vacuum divided by the speed of light in the material in question.
How is the refractive index of one medium with respect to the otherrelated to the speed of light?
The refractive index of any substance is(speed of light in vacuum)/(speed of light in that substance) .The number is greater than ' 1 ' in any material medium.
What happens to speed of light from vacuum to glass?
The speed of light is greatest in vacuum, and somewhat less in any material medium. The exact number depends on the individual material. They're all different.
What is the formula for the speed of light and which light between gamma rays and radio have the highest speed?
The formula for the speed of light, in vacuum, isc = 299,792,458 meters/second . where ' c ' is the speed of light.In any material substance, the speed of light isc/(the index of refraction for that substance) . Gamma rays, radio waves, and all other members of the electromagnetic spectrumbetween those, all have the same speed.
What is the relationship between energy and the speed of light?
E= hc/x
What is affects the speed of a light wave?
Light changes speed when it passes through a transparent substance, based on the refractive index. For diamond, the dense crystal slows light to less than half of its velocity as measured in a vacuum.
Does laser light color affect the speed at which it travels?
No the speed of light is independent of the color. The speed of light is dependent on the optical refractive index of the material or medium it is travelling through (in a vacuum light of any color has a speed equal to about 299,792,458 meters / second)
What is the radio wave speed range for visible light?
There's no 'range'. The speed of any electromagnetic signal, including light, is 299,792,458 meters (186,282 miles) per second in vacuum, somewhat slower in any material, depending on the material, regardless of wavelength.
