what is the velocity of light?

Answer 1

3 * 10^8 m/s

Answer 2

Velocity of light
Since 1983, by definition the velocity of light in a vacuum has been 299,792,458 meters per second. No experimental results can alter this value. It is a matter of definition because in that year the CGPM redefined1 the meter to base it on the velocity of light, rather than on a count of wavelengths of light emitted by krypton-86 atoms, or, as it was even earlier, on marks on a metal bar, the International Prototype of the Meter. See meter. In physics, the symbol for the velocity of light is "c".

The velocity of light is constant in the sense that, unlike the velocity of moving objects, it is independent of the observer's inertial frame of reference, a perennially astonishing insight famously owed to Albert Einstein. But the velocity does vary with the medium through which the light is passing; it is faster in a vacuum than, say, in water, glass or air. The functionality of lenses depends on this variation.

The velocity of light also varies with the velocity of the medium through which it is traveling. If a person walks at a velocity of 4 miles per hour up the aisle of an airplane traveling 300 miles per hour, his forward velocity is 304 miles per hour. But light does not behave this way! A. H. L. Fizeau (1819–1896) demonstrated that the velocity of light and the medium don't simply add; they are related thus:

velocity of light in medium:c/n+Vm(1+1/n power 2),

where n is the refractive index of the medium and Vm its velocity.

In a rather extraordinary feat, beginning in the late 1990's researchers were able to slow a pulse of light to a crawl, and even stop and restart it without destroying it2.

Answer 3

The velocity of light depends on the medium through which it is travelling.
The maximum velocity light could achieve is in vacuum and it is 299,792,458 meters per second. The common way of calculating the astronomical distances is a light year i.e. distance travelled by light in one year.

In some experimental conditions, scientists were able to slow down the light and in some cases they could even halt the light.

Answer 4

velocity of light is the speed with which a ray of light travels in a medium.It is the characterstic of a medium.for free space it is 3times ten raised to the power 8 meters around 300000 kms.This is the maximum attainable speed for a light ray as well as any real body.Whenever light travels in any other medium it has a velocity less than this as any other medium is obviously denser than free space.Also velocity of light inversely varies with the density of the medium.

Answer 5

SPEED OF THE LIGHT IN VACCUM
IF U WANA NO THE SPEED IN ANY OTHER MEDIUM DO ASK.


The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning "swiftness". It is the speed of all electromagnetic radiation in a vacuum, not just visible light.

In metric units, c is exactly 299,792,458 meters per second (1,079,252,848.8 km/h). Note that this speed is a definition, not a measurement. Since the fundamental SI unit of length, the meter, has been defined since October 21, 1983 in terms of the speed of light; one meter is the distance light travels in a vacuum in 1/299,792,458 of a second. Thus, any further increase in the precision of the measurement of the speed of light will actually change the length of the meter; the speed of light will remain precisely 299,792,458 m/s. In imperial units, the speed of light is about 186,000 miles per second, that is about one foot per nanosecond.

Answer 6

Albert Einstein constantly wondered what it would be like to ride on a beam of light.
Velocity = Frequency x Wavelength

Velocity = 2450 MHz x0.122 m

Velocity = 2.99x10 to the power of eight m/s

Answer 7

Velocity Of LIGHT
The velocity of light changes from medium to medium, due to it's refractive index.
The refractive index of light in vacuum is 0 (zero), therefore the speed of light in vacuum is 299,742,458 m/s( approx).
Sorry there's difference between velocity and speed.

Answer 8

In metric units, c is exactly 299,792,458 meters per second (1,079,252,848.8 km/h). Note that this speed is a definition, not a measurement. Since the fundamental SI unit of length, the metre, has been defined since October 21, 1983 in terms of the speed of light; one metre is the distance light travels in a vacuum in 1/299,792,458 of a second. Thus, any further increase in the precision of the measurement of the speed of light will actually change the length of the meter; the speed of light will remain precisely 299,792,458 m/s. Converted to imperial units, the speed of light is approximately 186,282.397 miles per second, or 670,616,629.384 miles per hour, or almost one foot per nanosecond.

Answer 9

the speed at which light reaches the earth surface is velocity of light

Answer 10

its 3 * 10^8 m/s