WEBVTT
1
00:00:01.940 --> 00:00:04.429 A:middle L:90%
we're told that the two plane mirrors on an angle
2
00:00:04.519 --> 00:00:08.349 A:middle L:90%
fatal one of 50 degrees with one another, and
3
00:00:08.349 --> 00:00:10.009 A:middle L:90%
, uh, we're asked to look at figure p
4
00:00:10.009 --> 00:00:14.240 A:middle L:90%
22.14 And it says if the horizontal rays incident on
5
00:00:14.240 --> 00:00:17.460 A:middle L:90%
Mir one at what angle fated to does the outgoing
6
00:00:17.460 --> 00:00:20.949 A:middle L:90%
reflected Ray make with the surface of mirrors, too
7
00:00:21.579 --> 00:00:23.969 A:middle L:90%
? Okay, so we can use the law of
8
00:00:23.969 --> 00:00:26.719 A:middle L:90%
reflection and geometry to find the angle of the outgoing
9
00:00:26.719 --> 00:00:29.160 A:middle L:90%
reflected raid that it's gonna make with the surface of
10
00:00:29.160 --> 00:00:32.750 A:middle L:90%
Mir. Two. Um, so the angle between
11
00:00:32.750 --> 00:00:35.340 A:middle L:90%
the two mirrors they don't want is equal to 50
12
00:00:35.340 --> 00:00:38.759 A:middle L:90%
degrees, and the figure from geometry the angle.
13
00:00:38.770 --> 00:00:41.850 A:middle L:90%
The incident rain makes with mere one is equal to
14
00:00:41.850 --> 00:00:44.500 A:middle L:90%
the angle between the two years. Hence, the
15
00:00:44.500 --> 00:00:47.100 A:middle L:90%
angle made by the incident rate on Mir one,
16
00:00:47.109 --> 00:00:54.710 A:middle L:90%
which we call 51 is equal to ADA one,
17
00:00:56.840 --> 00:01:03.549 A:middle L:90%
so 51 is equal to 50 degrees. So by
18
00:01:03.549 --> 00:01:06.459 A:middle L:90%
the law of reflection, the angle of incidence is
19
00:01:06.459 --> 00:01:07.459 A:middle L:90%
equal to the angle of reflection. So hence the
20
00:01:07.459 --> 00:01:11.170 A:middle L:90%
angle made by the reflected Ray with mere one,
21
00:01:11.239 --> 00:01:14.170 A:middle L:90%
which is 52 is going to be equal to 51
22
00:01:14.739 --> 00:01:21.409 A:middle L:90%
so we have. Fight too is equal to fly
23
00:01:21.409 --> 00:01:25.650 A:middle L:90%
. One. Therefore, fight too is equal to
24
00:01:25.659 --> 00:01:26.689 A:middle L:90%
a fatal one. Right. So fight, too
25
00:01:26.689 --> 00:01:30.549 A:middle L:90%
is equal to 50 degrees with some of the interior
26
00:01:30.549 --> 00:01:33.359 A:middle L:90%
angles of a triangle is always gonna be 180 degrees
27
00:01:33.370 --> 00:01:34.819 A:middle L:90%
. So fatal. One plus fight to plus five
28
00:01:34.819 --> 00:01:38.469 A:middle L:90%
three is going to be equal to 180 degrees,
29
00:01:38.469 --> 00:01:41.230 A:middle L:90%
and we need to find+53 So we'll just write
30
00:01:41.230 --> 00:01:44.140 A:middle L:90%
down what I just said. They don't want plus
31
00:01:45.239 --> 00:01:53.150 A:middle L:90%
fight too. Plus 53 is equal to 180 degrees
32
00:01:55.099 --> 00:02:00.819 A:middle L:90%
so we can solve for 53 So 53 is going
33
00:02:00.819 --> 00:02:07.170 A:middle L:90%
to be equal to 180 degrees, minus data one
34
00:02:07.500 --> 00:02:09.300 A:middle L:90%
minus phi, too. But fight to is equal
35
00:02:09.300 --> 00:02:13.710 A:middle L:90%
to theta one, so this is minus two beta
36
00:02:13.710 --> 00:02:15.520 A:middle L:90%
. One they don't want is equal to 50 so
37
00:02:15.520 --> 00:02:24.879 A:middle L:90%
this is equal to 80 degrees. So again,
38
00:02:24.949 --> 00:02:28.099 A:middle L:90%
finally, by the law of reflection, the angle
39
00:02:28.099 --> 00:02:30.289 A:middle L:90%
of incidence is equal to the angle of reflection.
40
00:02:30.430 --> 00:02:32.289 A:middle L:90%
So the angular reflected Ray makes with mere two is
41
00:02:32.289 --> 00:02:36.379 A:middle L:90%
going to be 80 degrees. So faded, too
42
00:02:38.939 --> 00:02:45.199 A:middle L:90%
, which is equal to 53 is equal to 80
43
00:02:45.199 --> 00:02:51.349 A:middle L:90%
degrees. That could be boxing as our solution.
44
00:02:52.030 --> 00:02:52.680 A:middle L:90%
The question