physics
posted by ceasar .
calculate the refractive index for a ray travelling from air to water given that the angle of incidence is 30degrees and the angle of refraction in the water is 22 degrees.Determine the speed of the ray in water.

Nair*sin30 = Nwater*sin22
(It's called Snell's law).
Nair = 1.0003 (or just use 1.00)
Solve for Nwater
You should get about 1.33 for Nwater
The speed of light in water is
c/Nwater, or about 3/4 c