00:00okay students hello
00:05I upon
00:10centrifugal force
00:15centrifugal force
00:20centrifugal force
00:25centrifugal force
00:30centrifugal force
00:35centrifugal force
00:40centrifugal force
00:45centrifugal force
01:20I have not gone anywhere, I am teaching right in front of you
01:24If I have said that there is a pseudo force, then you will be able to see the force
01:35Yes, understood?
01:38Centrifugal force and its other name is pseudo force
01:44So it seems that this is the main point
01:48I had told you about pseudo force in NLM
01:52When an observer observes an object sitting in a non-inertial frame
01:58In that condition, pseudo force is applied
02:02Hello!
02:04Any problem?
02:18Why do you keep coughing?
02:24Why?
02:26I have studied
02:28For the pain of a single tooth
02:34I have studied
02:40Only pseudo force is left to teach, rest all the forces have been taught
02:50Horizontal circular motion, vertical circular motion, uniform, non-uniform
02:56Yes, banking, all have been taught, only this child is left
03:00Study it well, you will understand
03:02You will be able to ask questions
03:04Yes, so let's move ahead
03:08See, I have just told you about centrifugal force, not pseudo force
03:16For this, we will sit in a non-inertial frame
03:21Where will we sit?
03:24What is a non-inertial frame?
03:27There are two types of frames, one is inertial and the other is non-inertial
03:32In inertial frame, we have rest frame and constant velocity frame
03:37These two frames are inertial
03:40If the body is at rest, then inertial frame
03:45Yes, when there is no exhalation, inertial frame is there
03:50And when there is exhalation, non-inertial frame is there
03:54Now, there is rotation motion, circular motion
03:57So, in circular motion, centripetal exhalation will be there always
04:02Whenever there will be circular motion, centripetal exhalation will be there
04:07If there is centripetal exhalation, then there is exhalation
04:10And if there is exhalation, then which frame will be there?
04:13Non-inertial frame
04:17Yes, when we sit on non-inertial frame and observe the object, then pseudo force is applied
04:28Some people apply pseudo force anywhere, the problem comes there
04:34Now, we are on earth, so we are in respect of earth
04:52By the way, earth also exhalates
04:55Now, we are sitting on earth
04:58Now, you are sitting here, then what will you say?
05:01You are running
05:02No, you will say, you go around once in a year
05:16Come here
05:21Come, let's go
05:24So, you run once in a year
05:27If you run once in a year, then centripetal exhalation will be there
05:32If there is circular motion around the sun, then centripetal exhalation will be there
05:36So, it doesn't mean that we are sitting on non-inertial frame of earth
05:43We don't take non-inertial frame, we are taking it in respect of it
05:47Let's come back to our concept
05:50Now, here you don't know about earth
05:53We have taken a disc, the disc is rotating
06:03Now, you are sitting on a football and observing a volleyball
06:11Now, any body, not circular, any body is rotating
06:17Yes, if you sit on it and observe, then pseudo force will be applied
06:22It doesn't mean that body is rotating
06:25Just pseudo force is applied, then we say answer is not coming
06:35No, you are in centripetal frame, you are on rest
06:43Yes, now you rotate it
06:47You are sitting, so put the motor below and rotate it
06:52Yes, so
06:55Circular, if there is circular motion, then when you observe in rotating frame, not non-inertial
07:03So, in that condition, pseudo force is applied
07:06What happened?
07:08We are showing for that
07:11Everybody will write
07:14Write, write, write
07:20Pen, Observer, we write here
07:23Observed
07:39Observer, observe
07:47An object
07:53Observer
07:59Observer
08:24Observer
08:32Observer
08:45Observer
08:53when observer observe an object from non-inertial frame
09:22then pseudo force acts on the object
09:44now what is its direction? what is its value?
09:58sir, from where are you taking the class?
10:08house number
10:28see, now see about pseudo force
10:32why do we take pseudo force away from the center?
10:36see, now we are sitting in non-inertial frame
10:40now in non-inertial frame means in circular motion
10:44centipetal acceleration is towards center
10:48hello, now in the frame in which we are sitting
10:54its acceleration is towards center
10:58so on the object which we observe, pseudo force will be applied opposite to this acceleration
11:04as I have taught in NLM, the object on which we are sitting in non-inertial frame
11:10its acceleration will be applied opposite to pseudo force
11:14so here centipetal acceleration is towards center
11:18so pseudo force is applied away from center
11:22hello, why?
11:28so pseudo force will be applied away from the center
11:34its value is m r perpendicular
11:38see, this body which we observe
11:42this is very important point, write it easily
11:46this body is rotating and this is its axis of rotation
11:50what is this axis of rotation?
11:54axis of rotation
11:58from axis of rotation, we will draw perpendicular on this body
12:02so we take perpendicular distance here
12:06f pseudo will be m r omega square
12:10this is not the value of centipetal force, its v square upon r or r omega square
12:14we take here
12:18we will take r omega square
12:22and here we take r perpendicular
12:26on this axis of rotation, perpendicular distance from this body
12:30if you have any problem, you can ask me
12:34here we are observing this
12:38here we are observing this
12:42here we are observing this
12:46now earth's axis of rotation will be
12:50on that axis of rotation, we will draw perpendicular
12:54now wherever sun is, we will see it there
12:58so here body is here
13:02body is kept here
13:06any problem?
13:10you can also
13:14now you will be given circular motion
13:18for that you can read it
13:22today it will be completed, by the way pseudo force is also completed
13:26this is all, we observe pseudo force from non inertial frame
13:30and here away from the center will be
13:34m r perpendicular omega square, this is its value
13:38this is called centrifugal force
13:42we call it pseudo force
13:46if we will ask you questions, your problems will be solved
13:50see, death well
13:54did you hear the name?
13:58so in death well we have made this diagram
14:02this is called rotor
14:06yes
14:10see, here we have taken death well
14:14what is rotor? there is a little difference between death well and rotor
14:18in death well, it is in the shape of well
14:22in rotor, the lower platform
14:26no, this is removed later
14:30we will make the diagram of rotor
14:34we have made the diagram
14:38see, we have taken this rotor
14:42now here I have made you stand
14:46no, you are going to do darshan
14:50so before that
14:54you do some tail
14:58pseudo force
15:02see, here
15:06no problem
15:10see, this rotor is rotating with omega
15:14this will be its rough surface
15:18there is rotation
15:22it rotates like this
15:26clockwise, anticlockwise
15:30see, here
15:34its mass is m
15:38we observe it sitting here
15:42we observe it sitting in non-inertial frame
15:46so this is non-inertial frame
15:50so we have to observe it sitting here
16:00see, we will observe it sitting here
16:04it will be seen on rest
16:08what?
16:12no, that is death well
16:16we have to stand here
16:20we are sitting on rotor
16:24rotor is in cylindrical shape
16:28this is a bottle
16:32close it
16:36to understand the difference
16:40this is a bottle
16:44so we are observing it sitting here
16:48this is the lower platform
16:52this will be removed later
16:56this is the lower platform
17:00so we can open it
17:04so this platform should be removed
17:08so that it does not fall
17:12so that it does not fall
17:16so that it does not fall
17:20so that it does not fall
17:24why do they swing?
17:26to have fun
17:28so people stand here also to have fun
17:32if cylinder is closed
17:36there will be a gap
17:40closed from top and bottom
17:44so people do not go for fun
17:48they go for fun
17:52those who like it, they go
17:56some people go to safari park
18:00jungle safari
18:04to see lion
18:08to see lion
18:12they go to see lion there
18:16lion can attack
18:20but it is a feeling
18:24people like to see lion
18:28they will stand in death well
18:32no one will be caught
18:36there is nothing to catch
18:40you have to stand free
18:44you have to stand free
18:48a little different feeling
18:50to get that feeling
18:52ok
18:54have you got the feeling?
18:56hello
18:58hello
19:02imagine
19:04now when you stand here
19:06now when you stand here
19:08the pseudo force on it
19:10in this direction
19:14because its centripetal acceleration
19:16axis of rotation will be towards center
19:18so pseudo force will be towards outside
19:20here normal reaction will be applied
19:22if its a rough surface
19:24friction will be applied
19:26towards top
19:32yes
19:38mg will be downward
19:40normal reaction will be perpendicular to surface
19:42pseudo force
19:44will be
19:46axis of rotation
19:48centripetal acceleration will be in this direction
19:58normal will be inside
20:00perpendicular to surface
20:04this will be f pseudo
20:10and here fs limiting
20:12and this will be seen on rest
20:18now if you have any problem
20:20you can ask
20:28see
20:30we don't apply centripetal
20:32it happens
20:34because of that pseudo force is applied
20:36sitting there
20:38this is the problem
20:40we apply mg
20:42normal
20:44pseudo
20:46centripetal acceleration
20:48when pseudo will be applied
20:50not centripetal
20:52we are sitting here
20:54it is seen on rest
20:56here we have shown force
20:58mg will be downward
21:00friction will be upward
21:02normal reaction will be here
21:04pseudo will be here
21:06is there any other force?
21:08no
21:12can you see?
21:14now from here we can see
21:16if it is seen on rest
21:18then what will be the acceleration?
21:20zero
21:26hello hi
21:30no both of them
21:32see
21:34value of m
21:36will be equal to f pseudo
21:38can you see?
21:40yes
21:42perpendicular to surface
21:44normal
21:46perpendicular to surface
21:48this is the surface
21:50this is like this
21:52perpendicular to surface
21:54body is here
21:56it will be applied here
21:58it is not applied upward
22:00value of m
22:02is mass
22:04m
22:06radius is r
22:10omega square
22:12this is first equation
22:14mg
22:16equal to fs limiting
22:22value of fs limiting
22:24will be mu s into n
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