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[Aragon]

An intense pencil of light strikes a parallel-sided plate of glass as shown. Several pencils of lower intensities are observed to leave the glass plate in the directions shown. If the thickness of the glass is given by t = 3.2 mm, the initial angle of incidence is phi = 17.60°, and the index of refraction of the glass is 1.46, what is the path length that the light travels inside the glass from its entry to the last exit on the diagram?



http://galileo.physics.fsu.edu/teacher/capalibrary/Graphics/Gtype73/prob24.gif

[Xetox]

Well that sucks I was going to cheat



http://galileo.physics.fsu.edu/teacher/capalibrary/Graphics/Gtype73/



But I dont have access to this site



I will find that answer

[Tristian]

probably the first one. (i can't remember how do this this **** anymore)

tristian

[Aragon]

Come on guys... isnt it obvious?





After the initial refraction, the beam is reflected in such a way as to strike the point of exit of each of the successive beams. So use Snell's law to find the angle of refraction upon entry, and then

path length = 7h



where h = t/sin theta

(t is the thickness of the glass, theta is the angle of transmission)

[Xetox]

I knew that ~~~~ was just waiting to C if anyone else did