00:01
So we can see in this problem, we have to check some of ptolemy's calculations in using snell's law.
00:07
And so we know that the angle of incident divided by the angle of refraction is supposed to be a common ratio.
00:18
And so i won't go through and calculate all of these.
00:23
But i will say that you have to make sure that you don't use this as 15 .3.
00:27
That is just 15 degrees, 30 minutes, and 30 out of 60, is that's 15 .5.
00:33
You may have a calculator that you can plug things in in terms of degrees and minutes, but most of the time i just convert them into a decimal.
00:43
And for 30, that's supposed to be 22 .5 degrees, et cetera.
00:48
And we go all the way down to the last one.
00:51
And it is kind of amazing that, you know, we take for granted that they do.
00:58
Did an awful lot way back when without all the materials that we have.
01:02
So make sure you're calculating there's in degree mode.
01:04
Let's just calculate a couple of these.
01:06
So if i have sign of 10 degrees and i divide it by the sign of 8 degrees, let's see what we get.
01:14
We have about 1 .25.
01:17
Let's take the sign.
01:19
I'll just go back and reenter those values in and just change those angles.
01:24
So we have that's going to be 20 degrees.
01:28
And oops, i see i made a mistake here.
01:30
I didn't put the sign down...