Angle refraction from a point on glass.

[rcmango]

Homework Statement

The drawing shows a rectangular block of glass (n = 1.52) surrounded by liquid carbon disulfide (n = 1.63). A ray of light is incident on the glass at point A with a = 36.0° angle of incidence. At what angle of refraction does the ray leave the glass at point B?

Please explain a way to reach the solution for this problem. I tried using the equation: n2*sin(36) / n1

pic: http://img128.imageshack.us/img128/900/13113445ga1.png

Homework Equations

The Attempt at a Solution

not sure why this would not work: sin(B) = n1/n2 * sin(a)

so, 1.63/1/52 * sin(36) comes to 39.1 degrees??

please correct me if this is incorrect. However, the answer doesn't seem to be accurate. This is the angle that is refracted from the glass at B correct?

thanks.

 

[klile82]

You're using Snell's Law correctly, but I think this is a two-part problem. So first, you need to apply it to find the angle of refraction into the glass at point A. This is the angle you solved for. You need to use that angle to apply Snell's law again at point B, to find the angle at which the light leaves the glass at point B.