Hello, all

First time poster, long-time community follower. Here's the deal: I'm currently studying to become an optician, and, at present we are studying Light. When it comes to the theory-side of things, i'm actually getting the hang of it all, but... when it comes to the mathematics... Well, I need help. This place seems to be the Internet's mecca when it comes to all things Math, so I figured I'd see if any of you guys and girls could post-up some answers (with working-out) to the following questions I'm having issue with. Here are the questions:

1/ If the angle of incidence of a ray of light entering a rectangular glass block is 42 degrees and the angle of refraction is 26 degrees, what is the refractive index of the glass to air?

2/Calculate the angle of refraction which results when a light ray is incident at 35 degrees to the surface of a rectangular block of material of refractive index n=1.614.

3/ If light strikes the surface of a block of transparent material at an angle of incidence of 42.4 degrees and is deviated by 19.4 degrees, what is the refractive index of the material?

4/ Calculate the critical angle for an interface between a high index plastic material (n=1.602) and perspex (n=1.490).

5/ Light traveling inside a block of optical material makes an angle of 36.5 degrees to the normal. The angle of incidence is 67.48 degrees. What is the speed of light inside the material?

6/ Calculate the amount of deviation which occurs when a light ray strikes the surface of a block of optical material at 38 degrees and slows down to a speed of 1.91x10(to the power of 8) m/sec.

7/ Calculate the path of a ray of light approaching the inside surface of a block of material (n-1.654) at an angle of 26.7 degrees.

You help with these questions would be of great assistance to me. Thank you very much in advance!