What is The Speed of Light ?
Answers
Answer:
3×10^8 m/s or 3×10^5 km/s
Explanation:
The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its exact value is defined as 299792458 metres per second (approximately 300000 km/s, or 186000 mi/s[Note 3]). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time interval of 1⁄299792458 second.[Note 4][3] According to special relativity, c is the upper limit for the speed at which conventional matter, energy or any information can travel through coordinate space. Though this speed is most commonly associated with light, it is also the speed at which all massless particles and field perturbations travel in vacuum, including electromagnetic radiation (of which light is a small range in the frequency spectrum) and gravitational waves. Such particles and waves travel at c regardless of the motion of the source or the inertial reference frame of the observer. Particles with nonzero rest mass can approach c, but can never actually reach it, regardless of the frame of reference in which their speed is measured. In the special and general theories of relativity, c interrelates space and time, and also appears in the famous equation of mass–energy equivalence E = mc2.[4] In some cases objects or waves may appear to travel faster than light even though they don't actually do so, e.g., with optical illusions, phase velocities, certain high-speed astronomical objects, particular quantum effects, and in the case of the expansion of space itself.
Astronomical units per day : 173
Miles per second : 186000
Metres per second : 299792458
Miles per hour : 671000000
Kilometres per hour : 1080000000
Parsecs per year : 0.307
From Sun to Earth (1 AU) : 8.3 min
hope it helps you