# Parallel slabs? I think not!

Classical Mechanics Level 5

A laser beam propagates through a region whose refractive index varies as $$\mu = \mu_0 (\frac{r}{r_0})$$. At a distance of R the beam makes an angle of 30 degrees with the normal.

Find the minimum separation between the beam and the center of this region(the point where $$r=0$$) in cm.

Assume $$\mu_0= 1$$, $$r_0= 3 \text{cm}$$, $$R= 8\sqrt2\text{ cm}$$.

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