# Exercise 5.1.1 Derivation of Snellius Law

| Consider the situation as given in the figure.
|  | Assume that the light consists of a stream of photons, all with the same energy hn and with momentums given by k.
|  | Assume a certain flux of photons (= number per second and cm2) given by Iin, Iref, and Itr. Also assume that you have "mirror" reflection, i.e. both angles are identical (= a)
| Show that you obtain Itr = Iin – Iref and Snellius law (sina/sinb = n) from energy and momentum conservation.
| Link to the solution

With frame

5.1.1 What is Light?

Solution to Exercise 5.1-1: Derivation of Snellius Law

© H. Föll (Advanced Materials B, part 1 - script)