Key Concepts
* Refraction: Light bends when it passes from one medium to another because the speed of light changes.
* Index of Refraction (n): This is a measure of how much light slows down in a medium compared to its speed in a vacuum.
* Speed of Light in Vacuum (c): Approximately 299,792,458 meters per second (m/s).
Calculations
1. Speed of Light in Water:
* Water's index of refraction (n) is approximately 1.33.
* Speed of light in water (v) = c / n = 299,792,458 m/s / 1.33 ≈ 225,407,148 m/s
2. Speed of Light in Air:
* Air's index of refraction is very close to 1, meaning light travels almost as fast in air as it does in a vacuum.
* Speed of light in air (v) ≈ c ≈ 299,792,458 m/s
Conclusion
When a light beam emerges from water into air, its speed increases from approximately 225,407,148 m/s to nearly 299,792,458 m/s. This is because light travels faster in a medium with a lower index of refraction.
Important Note: The concept of "average light speed" during the transition isn't quite accurate. The speed of light changes instantaneously as it passes from water to air.
