00:01
Okay, so i'm in new chapter 32, problem 80 now.
00:04
And it says, has a prism here at an apex angle phi.
00:10
And we want us to know if the angle phi is 72 degrees.
00:16
What is the minimum incident angle for the ray if it is to emerge from the opposite side, which is not the total internally reflected? if thin is 1 .58.
00:30
Okay.
00:32
So for the refraction on the second surface, let's draw this again, actually, we're going to get a better view here of the refractions here.
00:43
So we have an incident right here.
00:45
This is at theta 1.
00:48
And this is going to get emerged here at a theta 2, which is thus entering this one at a theta 3 and then exits at a theta 4.
01:02
So if we look at the second case of refraction in the face instead of our smells law, we should have in for the glass.
01:12
Sign theta three equals in air is just one.
01:17
So sign theta four...