2006-10-10 17:48:05 · 24 answers · asked by Sharath M 1 in Science & Mathematics ➔ Physics
Exactly 299,792,458 meters per second. How do we know it exactly? Because it's defined as a primary standard. The length of the standard meter now depends on our ability to measure the velocity of light.
2006-10-10 17:53:15 · answer #1 · answered by injanier 7 · 3⤊ 1⤋
Scientists have learned through experimentation that light behaves like a particle at times and like a wave at other times. The particle-like features are called photons. Photons are different from particles of matter in that they have no mass and always move at the constant speed of about 300,000 km/sec (186,000 mi/sec) when they are in a vacuum. When light diffracts, or bends slightly as it passes around a corner, it shows wavelike behavior. The waves associated with light are called electromagnetic waves because they consist of changing electric and magnetic fields.
2006-10-11 01:33:50 · answer #2 · answered by Ryan 3 · 1⤊ 0⤋
3*10^8
3 X 10 raised to the power 8
2006-10-11 04:48:57 · answer #3 · answered by Santhosh S 5 · 0⤊ 1⤋
The perfect answer is 2.998797*10^8 m/s and the approximate value is 3*10^8 m/s. The exact value was determined by Sir. Michelson in 1928
and the answer is the first one.
2006-10-11 01:22:15 · answer #4 · answered by Enrique 2 · 1⤊ 0⤋
its speed is 3*10^8 m/s
2006-10-11 15:22:50 · answer #5 · answered by juschill 1 · 0⤊ 0⤋
The speed of lignt quanta in Vacuum is c=1.
And in the atom it speed is c>1
( it transforms in the electron).
2006-10-11 11:52:16 · answer #6 · answered by socratus 2 · 0⤊ 0⤋
3*10^8 m/sec
2006-10-11 05:40:36 · answer #7 · answered by gaurav a 1 · 0⤊ 1⤋
3 times ten to the power of eight meters per second.
2006-10-11 00:56:17 · answer #8 · answered by Aurthor D 4 · 0⤊ 2⤋
Acording to me it should b 3.0 x 10power8
2006-10-11 01:02:33 · answer #9 · answered by Trotro 1 · 0⤊ 1⤋
it's 3 lac kilometers per second. that is 3*10^^5 kmps
2006-10-11 00:56:34 · answer #10 · answered by Bunty Rocks 2 · 0⤊ 2⤋