Our Discord hit 10K members! 🎉 Meet students and ask top educators your questions.Join Here!

# A ray of light traveling in air strikes a flat $2.00 \mathrm{cm}$ thick block of glass $(n=1.50)$ at an angle of $30.0^{\circ}$ with the normal. Trace the light ray through the glass, and find the angles of incidence and refraction at each surface.

## The angles of incidence and refraction at the first surface are $30.0^{\circ}$ and $19.5^{\circ}$, respectively. The angles of incidence and refraction at the second surface are $19.5^{\circ}$ and $30.0^{\circ}$, respectively.

### Discussion

You must be signed in to discuss.
##### Christina K.

Rutgers, The State University of New Jersey

##### Andy C.

University of Michigan - Ann Arbor

##### Aspen F.

University of Sheffield

### Video Transcript

here. I've made a picture off What is happening? A rail flight goes through a piece of glass. Let's denote this angle as angle of incidence. One this angle as angle of refraction. One this angle is em off incidents to and this angle as angle of refraction, too. Please note that from basic geometry, the angle of refraction one is equal to the angle off incidents to since this angles are equal to each other. Let's do you know both of them as powerful. Let's write down snails lower for the first pair off angles. Sign off the anger off refraction. One equal stare a show off refractive indices off air and glass multiplied by this sign off the angle of incidence one. Please note that the refractive index off air is equal to one and the angle of refraction one is equal toe Alfa. Let's rewrite this equation. Taking these facts into account. Sign off equals one over the refractive index of gloves multiplied by this side over the angle of Incidence one. Let's now right down, snail slow for the second pair of angles. Sign off the angle off. Refraction too equal. Stare a show off. Refractive indices off glass and air multiplied by this side off the angle off. Easy aliens to which is equal toe Alfa. Please note that sign Alpha is already written in terms off the known co entities in order to find the angle of refraction to let's substitute the expression for Sign Alfa into the second equation. Sign off. The angle of refraction, too, is equal tow N G multiplied by sine off. In other words, multiplied by this expression, please note that N g councils out. Let's now isolate off from this equation and off our two from this equation, Alpha equals Arctic sign off the right side off our to equals arc side for the right side. Let's now use a calculator to substitute the numbers off equals How far are one? Because off I to and he close to 19.5 degrees Alfa are too equals off. I won and he close to suit. He agrees. Please note that in both cases I am required to round the on servers. 23 significant figures

Saint Petersburg State University
##### Christina K.

Rutgers, The State University of New Jersey

##### Andy C.

University of Michigan - Ann Arbor

##### Aspen F.

University of Sheffield