Which Ray Will Reach the Second Plane First?

[AudioFlux]

In the diagram, there are two light rays that start from the same plane and fall on another plane which is parallel to the first one. The light ray P goes through a medium of higher refractive index than vacuum/air and refracts. So, which one of them will reach the second plane first? Ray P will travel a shorter distance compared to Q but will be slower than Q.

 

[sophiecentaur]

Apply Snell's law to find the path length. Then find the transit time. Just go through the exercise.
You could start with A=0...

 

[AudioFlux]

Apply Snell's law to find the path length. Then find the transit time. Just go through the exercise.
You could start with A=0...

I used the refractive medium as a glass slab, and used 30 deg as angle A(see the attachment).

Conclusion: P is slower than Q at 30 deg.

I think P will always be slower than Q.