# Determining Speed and Wavelength of Red Light in Plastic

## How can we calculate the speed and wavelength of red light in a medium like plastic?

What equation can we use to determine the speed of light in plastic? How can we find the wavelength of light in a medium?

## Calculating Speed and Wavelength of Red Light in Plastic

In order to calculate the speed and wavelength of red light in a medium like plastic, we can use the equations involving the speed of light in a medium and the wavelength of light in a medium.

The speed of light in a medium, such as plastic, is given by the equation v = c/n, where:
**v** is the speed of light in the medium,
**c** is the speed of light in vacuum (approximately 3 x 10^8 m/s), and
**n** is the refractive index of the medium.

To determine the speed of red light in plastic, we first need to know the refractive index of the specific plastic material.

The wavelength of light in a medium can be determined using the equation λ = λ0/n, where:
**λ** is the wavelength of light in the medium,
**λ0** is the wavelength of light in vacuum, and
**n** is the refractive index of the medium.

Given that the red laser has a wavelength of 633 nm (633 x 10^-9 m) in vacuum, we can calculate the wavelength of red light in plastic using the refractive index of the plastic material.