How much will a ray be deviated ?

[teyber]

How much will a ray be "deviated"?

So my terrible phys prof presented this question but failed
to answer it and I have become very curious of the answer
after failing to answer it several times.

Here is a quick paint drawing of my question:

http://img17.imageshack.us/img17/8624/deflection.jpg

Uploaded with ImageShack.us

A "blue" light ray passes through glass of thickness T. The entry
and exit angles are the same, but it is "deviated' by a difference
"x" as i tried to show in the figure. This distance is the distance from
the two parallel green lines. This is not in my textbook, but my prof
just said it is approximately the thickness T times the sin of the incident
angle. The textbook does not have this. Does anyone happen to know
this or know how to quickly prove this? thanks so much in advance.

Cheers

 

[berkeman]

So my terrible phys prof presented this question but failed
to answer it and I have become very curious of the answer
after failing to answer it several times.

Here is a quick paint drawing of my question:

http://img17.imageshack.us/img17/8624/deflection.jpg

Uploaded with ImageShack.us

A "blue" light ray passes through glass of thickness T. The entry
and exit angles are the same, but it is "deviated' by a difference
"x" as i tried to show in the figure. This distance is the distance from
the two parallel green lines. This is not in my textbook, but my prof
just said it is approximately the thickness T times the sin of the incident
angle. The textbook does not have this. Does anyone happen to know
this or know how to quickly prove this? thanks so much in advance.

Cheers

Welcome to the PF.

You would use Snell's Law to work on this problem. Are you familiar with Snell's Law?

http://en.wikipedia.org/wiki/Snell's_law

.