A cylinder with height 5.0 m is made by mixing materials with different indexes of refraction. The mixture is prepared such that the index of refraction is 1.0 on one end, 2.6 on the other end and varies linearly in between. How long does it take light to travel through the length of the cylinder?

Answer 1

N = 1 + 1.6 (x/L)
The speed of light at position x is
V = c/N
The light travel time is
the integral of dx/V from x = 0 to L
= the integral of dx/c * N(x) from 0 to L

Answer 2

Thanks a lot