# Rotating mirrors

1. Dec 4, 2007

### pardesi

Question
there are two discs rotating with angular speed $$\omega$$ in oppsite direction.Both of them have some number of mirrors attached to them in such a way that a light ray coming from a source kept in between them gets reflected n times at each mirror in one second .Find the angular speed $$\Omega$$
of such a ray.

Relevant Theory
if the mirror rotates by an angle $$\theta$$ and if the direction of incident ray is unchanged then the reflected ray turns an angle $$2\theta$$

Attempt
i don't understand the meaning of $$\Omega$$ here in some sense.basically no idea