How Does Light Refract Through Water and Crown Glass?

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A block of crown glass (refractive index - 1.52) is covered by a sheet of water (refractive index - 1.33). a ray of light incident on the water with a angle of incidence of 55 degrees. find the angle that this ray makes with the normal when it emerges from the glass...


PLEASE help, this is the only question i can't do...

thanks,

Regards Ryan Voy

ryanvoy@hotmail.com
 
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HINT: Apply Snell's Law at each of the three interfaces.
 
thanks i knew i had to do that but I am getting a different answer to the textbook,

My answer - 32.61 degrees'

text books answer 69.4 degrees

sorry 4 the trouble

Thanks regards Ryan

ryanvoy@hotmail.com
 
The answer should be exactly 55 degrees, and you can do this without even invoking Snell's law explicitly. As long as the sides of all the interfaces are perfectly parallel, the exit ray in the same medium has to be parallel to the incident ray in that medium.

EDIT : This is assuming that the glass is covered on only one side with water and the final ray emerges into air.
 
:smile: Thanks i will check Monday with the teacher, hopfully its right :smile:


Regards Ryan,

ryanvoy@hotmail.com
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
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