# Refraction - A light ray is incedent on a block of glass at an angle of 30 degrees

Refraction -- A light ray is incedent on a block of glass at an angle of 30 degrees

## Homework Statement

A light ray is incedent on a block of glass at an angle of 30 degrees,what is the angle of refraction.

Given: glass: 1.47
incident angle:30°

## Homework Equations

π1 sin θ1 = π2 sin θ2

## The Attempt at a Solution

I did: (1.47) sin (30)= π2 sin θ2
But I don't think this is the answer. i'm helping a friend but the problem don't say what the other medium is...

Last edited:

collinsmark
Homework Helper
Gold Member

Hello o0sunny0o,

Welcome to Physics Forums!

## Homework Statement

A light ray is incedent on a block of glass at an angle of 30 degrees,what is the angle of refraction.

Given: glass: 1.47
incident angle:30°

## Homework Equations

π1 sin θ1 = π2 sin θ2

## The Attempt at a Solution

I did: (1.47) sin (30)= π2 sin θ2
But I don't think this is the answer. i'm helping a friend but the problem don't say what the other medium is...
I'm guessing that the original medium is air. The second medium is glass.

I'll also assume that the 30o angle is measured with respect to the perpendicular*, and measured outside the glass (i.e. in the air). If so, treat your
n1 sinθ1 = n2 sinθ2
formula as
(Index of refraction of air)(sine of angle in air) = (index of refraction of glass)(sine of angle in glass)​

*The problem statement is is vague about what the angle is in reference to; perpendicular or parallel. I'm assuming it's in reference to the perpendicular, but that's just my assumption. I don't know for sure. A figure would certainly clear things up.