# How to Use Snell’S Law to Find Speed of Light?

How to Use Snell’S Law to Find Speed of Light

Snell’s Law is a fundamental principle in physics that describes the relationship between the angles of incidence and refraction when light passes through different mediums. By applying Snell’s Law, we can determine the speed of light in a given medium.

Credit: study.com

## Steps to Find the Speed of Light Using Snell’s Law:

1. Understand Snell’s Law: Snell’s Law states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant when light passes from one medium to another.
2. Measure the Refractive Index: Determine the refractive index of the medium using Snell’s Law formula: n = sin(i) / sin(r), where ‘n’ is the refractive index, ‘i’ is the angle of incidence, and ‘r’ is the angle of refraction.
3. Calculate the Speed of Light: Once you have the refractive index, you can find the speed of light in the medium using the formula: v = c / n, where ‘v’ is the speed of light, ‘c’ is the speed of light in a vacuum, and ‘n’ is the refractive index of the medium.

## Example Calculation:

Angle of Incidence (i) in degrees Angle of Refraction (r) in degrees Refractive Index (n) Speed of Light (v)
30 20 1.5 200,000 km/s

By following these steps and performing the necessary calculations, you can use Snell’s Law to find the speed of light in a given medium. Understanding this concept is crucial in the field of physics and optics.

### Conclusion

Using Snell’s Law to determine the speed of light allows us to gain insights into the behavior of light when it travels through different materials. By following the steps outlined above, you can confidently calculate the speed of light in various mediums based on their refractive indices.