The snells law states that the ratio of sine of angle of incidence to the sine of angle of refraction is always constant for two reasons. Snells Law illustrates the relationship between the angles of incidence and refraction for a wave intruding on an interface between two medium with different indices of refraction. Snells law gives a relationship between the angles of incidence and refraction.
Then Snells Law gives.
Sini 120342 041. In optics the law is used in ray tracing to compute the angles of incidence or refraction and in experimental optics to find the refractive index of a material. When light strikes a smooth barrier between two transparent materials the light is partly reflected and partly refracted transmitted. Refraction certainly explains why fishing with a rod is a sport while fishing with a spear is not 2.