Problem B.2: Escaping a Star (6 Points) It takes many years for a photon produced in a star's centre to reach its surface and escape into space. This is due to its constant interaction with other particles. To estimate the time it takes for a photon to escape a star's interior, we assume that the photon is deflected in equal time intervals into a random direction in a two-dimensional space (i.e., a random walk): At each step i, the photon moves a constant distance in an angle, thus changing its position: cos(4) sin(y) Ai, - c (a) Determine the distance R(n) from the centre (0,0) after n steps.
