WEBVTT
1
00:00:00.240 --> 00:00:03.399 A:middle L:90%
so the initial direction off motion is taken to really
2
00:00:03.399 --> 00:00:07.349 A:middle L:90%
positive extraction. This is also the direction off e
3
00:00:07.980 --> 00:00:11.269 A:middle L:90%
. So we'll be using the following question. The
4
00:00:11.269 --> 00:00:19.179 A:middle L:90%
F squared minus the initial squared he I squared equals
5
00:00:19.179 --> 00:00:24.809 A:middle L:90%
two to a aah Delta X to figure out Delta
6
00:00:24.809 --> 00:00:28.230 A:middle L:90%
X. So here we have the F, which
7
00:00:28.230 --> 00:00:31.089 A:middle L:90%
is the final velocity with zero. You know,
8
00:00:31.089 --> 00:00:35.149 A:middle L:90%
the exploration is basically force over Mass, which is
9
00:00:35.600 --> 00:00:40.750 A:middle L:90%
anarchist E times the electric field divided by mass of
10
00:00:40.750 --> 00:00:44.259 A:middle L:90%
the electron. And then we saw for Delta X
11
00:00:44.259 --> 00:00:47.710 A:middle L:90%
from here, which is so that's part A that
12
00:00:47.719 --> 00:00:51.450 A:middle L:90%
rendering. So let X is negative. The I
13
00:00:51.450 --> 00:00:57.049 A:middle L:90%
squared divided by two a, which is and e
14
00:00:57.640 --> 00:01:00.039 A:middle L:90%
So there's a negative sign. M e the I
15
00:01:00.039 --> 00:01:06.290 A:middle L:90%
squared, divided by to E. And then there
16
00:01:06.290 --> 00:01:12.459 A:middle L:90%
the native stands with, which gives us 9.11 times
17
00:01:12.469 --> 00:01:17.280 A:middle L:90%
10 to the power native. 31. That's Katie
18
00:01:18.609 --> 00:01:23.939 A:middle L:90%
times five. So that's B squared, so five
19
00:01:23.939 --> 00:01:29.909 A:middle L:90%
times tended bar six meters per second. Then we're
20
00:01:29.930 --> 00:01:34.140 A:middle L:90%
square here and then divide that by two Are times
21
00:01:34.140 --> 00:01:40.250 A:middle L:90%
electrics, electrons. Charges is 1.6 times tended bar
22
00:01:40.319 --> 00:01:45.950 A:middle L:90%
negative 19 Coolum and the electric field is one time
23
00:01:45.950 --> 00:01:49.900 A:middle L:90%
sent the bar three Newman Pakula, which gives a
24
00:01:49.900 --> 00:01:57.950 A:middle L:90%
7.2 Sorry, 7.12 times end of the bar.
25
00:01:59.390 --> 00:02:07.985 A:middle L:90%
Negative too meter. So for part B Ah,
26
00:02:07.985 --> 00:02:16.865 A:middle L:90%
we can use a question 2.17 17 Ah which gives
27
00:02:16.865 --> 00:02:23.514 A:middle L:90%
us d with his Delta X over the average velocity
28
00:02:24.444 --> 00:02:30.604 A:middle L:90%
which is s o the average velocity is basically the
29
00:02:30.604 --> 00:02:32.944 A:middle L:90%
initial plus the finals divided by two. And since
30
00:02:32.944 --> 00:02:36.745 A:middle L:90%
he finally zero, we have the initial by two
31
00:02:37.245 --> 00:02:40.185 A:middle L:90%
. So that gives us twice Delta X divided by
32
00:02:40.324 --> 00:02:49.844 A:middle L:90%
the average which is toward Ames 7.12 times 10 to
33
00:02:49.844 --> 00:02:54.504 A:middle L:90%
the power negative toe meter on, divided by the
34
00:02:54.504 --> 00:02:58.354 A:middle L:90%
average are the initial in that case. So that's
35
00:02:58.354 --> 00:03:07.224 A:middle L:90%
gonna be the initial Excuse me on DA The initial
36
00:03:07.224 --> 00:03:09.405 A:middle L:90%
is five times and for six meters per second,
37
00:03:09.995 --> 00:03:15.634 A:middle L:90%
which gives us 2.85 times 10 to the power negative
38
00:03:15.645 --> 00:03:21.854 A:middle L:90%
eight second Ah, in part C will be using
39
00:03:23.745 --> 00:03:29.395 A:middle L:90%
Delta V squared equals two twice off a Delta x
40
00:03:30.944 --> 00:03:32.784 A:middle L:90%
ah, with the new value off Delta X,
41
00:03:32.794 --> 00:03:37.914 A:middle L:90%
we see that delta K or change in kinetic energy
42
00:03:38.294 --> 00:03:44.694 A:middle L:90%
divided by the final kinetic energy is equal to Delta
43
00:03:46.435 --> 00:03:53.275 A:middle L:90%
Half and e V spread divided by half off m
44
00:03:53.284 --> 00:03:58.775 A:middle L:90%
e he I spread which is equal to Delta V
45
00:03:58.775 --> 00:04:04.072 A:middle L:90%
squared, divided by P I squared and from ah
46
00:04:04.081 --> 00:04:05.981 A:middle L:90%
, the above A question we see the Delta V
47
00:04:05.981 --> 00:04:12.102 A:middle L:90%
squared is equal twice off, eh? Delta X
48
00:04:12.192 --> 00:04:15.651 A:middle L:90%
divided by the I squared which is again can be
49
00:04:16.201 --> 00:04:23.612 A:middle L:90%
written is negative twice e ah Smalley Biggie Delta X
50
00:04:24.541 --> 00:04:30.742 A:middle L:90%
divided by and e the I squared now Ah,
51
00:04:30.922 --> 00:04:32.891 A:middle L:90%
using the given numbers, Let me write down the
52
00:04:32.891 --> 00:04:38.062 A:middle L:90%
numbers over here. So ease negative 1.6 times tend
53
00:04:38.062 --> 00:04:43.901 A:middle L:90%
to the bar Negative 19 Fulham Big e is end
54
00:04:43.901 --> 00:04:46.521 A:middle L:90%
of the bar three Newton for Coolum. Um,
55
00:04:46.531 --> 00:04:51.391 A:middle L:90%
Delta X is sorry. That's meant X is eight
56
00:04:51.451 --> 00:04:59.552 A:middle L:90%
kinds tend to the power negative three leader and ah
57
00:04:59.562 --> 00:05:04.141 A:middle L:90%
m is the weight off electron Witches are the mass
58
00:05:04.141 --> 00:05:09.791 A:middle L:90%
of the electron which is 9.11 times tentacle and then
59
00:05:09.791 --> 00:05:15.612 A:middle L:90%
get native Ah, 31 kg And finally we have
60
00:05:16.242 --> 00:05:20.012 A:middle L:90%
the initial velocity V I, which is equal to
61
00:05:20.021 --> 00:05:29.031 A:middle L:90%
five times 10 to the bar. Six meter R
62
00:05:29.221 --> 00:05:35.122 A:middle L:90%
. Sorry. Ah, meter per second. So
63
00:05:35.122 --> 00:05:38.531 A:middle L:90%
using all the numbers, we see that fine.
64
00:05:38.541 --> 00:05:41.932 A:middle L:90%
The final wish. Final value of Delta K over
65
00:05:41.932 --> 00:05:50.841 A:middle L:90%
K F is negative 0.112 So does the fraction of
66
00:05:50.841 --> 00:05:55.192 A:middle L:90%
the initial kinetic energy lost in that Ah, in
67
00:05:55.192 --> 00:06:05.622 A:middle L:90%
the region is 0.112 are 11 point 2%. All
68
00:06:05.622 --> 00:06:06.672 A:middle L:90%
right, Thanks for watching.