Comparison of Speed of Light in Air
The speed of light in a vacuum is approximately 299,792 kilometers per second. When light travels through a medium such as air, its speed is slightly slower due to the interactions between the photons and the molecules in the medium.
Factors Affecting Light Speed in Air
The speed of light in air is about 99.97% of its speed in a vacuum. This difference is primarily caused by the refractive index of air, which is slightly greater than 1. As light enters a medium like air, it interacts with the atoms and molecules, causing a delay in its propagation.
Calculation of Light Speed in Air
To calculate the speed of light in air, one can use the formula:
\[ v = \frac{c}{n} \]
Where:
– \( v \) is the speed of light in the medium
– \( c \) is the speed of light in a vacuum
– \( n \) is the refractive index of the medium
For air, with a refractive index of approximately 1.0003, the speed of light can be calculated as:
\[ v = \frac{299,792}{1.0003} \approx 299,702 \, \text{km/s} \]
Therefore, the speed of light in air is approximately 299,702 kilometers per second.
# physics, light speed