Problem P. 4005. (October 2007)

P. 4005. The walls of a room, which has a shape of a cuboid, are plane mirrors. The distance between the walls are a and b. A horizontal beam of light is generated at one of the walls, the angle between the light beam and this wall is alpha.

How much time elapses until the light reaches the same wall?

(3 pont)

Deadline expired on November 12, 2007.

Statistics:

139 students sent a solution.
3 points:	92 students.
2 points:	24 students.
1 point:	16 students.
0 point:	6 students.
Unfair, not evaluated:	1 solutions.

Problems in Physics of KöMaL, October 2007