8.01x - Lect 5 - Circular Motion, Centripetal Forces, Perceived Gravity
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- Опубликовано: 27 сен 2024
- Circular Motion - Centrifuges Moving - Reference Frames - Perceived Gravity
Lecture Notes, Orbital Information on Planets: freepdfhosting....
Assignments Lecture 5, 6, 7 and 8: freepdfhosting....
Solutions Lecture 5, 6, 7 and 8: freepdfhosting....
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I remember watching this lecture when I was in high school and was blown away at how cool physics could be. I’m now a second year PhD student in astrophysics, thanks Professor Lewin 🙏
want a cookie?
I want to be an astrophysicist. I’m taking honors physics right now in junior year of high school. I’m not ready yet, but I want to get better and one day become one.
@@shadeyfang8564 It is really cool of you. However, I want to be an astrophysicist too. I am just in 11th grade and try to emphasize my problem-solving and concept-clearing. Any suggestion can I get?
I'm in 10 th grade and want to study astrophysics... don't know wether my dream could ever come true or not
These lectures are very interesting as well informative...I like to watch them ...
Hi sir I'm 11th standard guy preparing for JEE mains & Advanced. So I'm watching you're lectures and these are very helpful . Thanks ❤
All the best
@@lecturesbywalterlewin.they9259 Thanks!
2025 aispirant
way to IIT is much difficult
@@makeitwithyashbcz he is goat 🐐
Sir, one thing I think it's incredible is that you post your lectures on Internet. It sure helps a lot of people, not only because they're really easy to understand and very memorable, but also because they're free. Thank you a lot, Mr. Lewin
0:00- uniform circular motion (+ex rotate disc) +Just introduce pull & push force (there is no such thing as a free lunch) + the motion after we cut the spring
12:40 - planet around the sun + diagram a - R + slope ~ 1/R^2
17:28 - basic ideal behind a centrifuge + experiment in order to dry the lettuce
22:25: the connection between centripetal acceleration and perceived gravity (such amazing)
32:00: explain about the experiment with a simple centrifuge
42:50: explain about the experiment with a bucket of water
Thanks to Walter Lewin, you make me feel happy every single lecture
You made the day easy.
Thanks
Tysm ❤️
Thank you 😊
It's an honour to be able to watch these lectures.
Thank you professor Lewin!
:)
@@lecturesbywalterlewin.they9259 😊
Dr. Lewin, Thank you so much for these amazing lectures. I have been out of academia for 4 years and my application for a PhD was recently accepted. I'm watching your videos to prepare for graduate studies and strengthen my foundations. I will remain forever in your debt!
You are very welcome
Never thought that I'd be able to attend mit lectures from home !
Thank you very much professor!
You are the best
Most welcome!
@@lecturesbywalterlewin.they9259THE UNDERSTANDING OF WHAT ARE GALACTIC JETS AND THE SOLUTION TO WHAT IS THE CORONAL HEATING “PROBLEM”:
Consider what is E=MC2. The stars AND PLANETS are POINTS in the night sky ON BALANCE. Two AND three dimensional SPACE are BALANCED. Great. (Indeed, consider TIME AND time dilation ON BALANCE.) This CLEARLY solves what is the coronal heating “problem”. REGARDING WHAT IS E=MC2, c squared CLEARLY AND NECESSARILY represents a dimension of SPACE (ON BALANCE). Great. I have CLEARLY proven what is the FOURTH DIMENSION. ELECTROMAGNETISM/energy is gravity.
What is E=MC2 is the reason why what are OBJECTS may fall at the SAME RATE. Great !!!!
By Frank Martin DiMeglio
Consider what is THE EYE ON BALANCE. Notice what is the BLUE sky. ELECTROMAGNETISM/energy is gravity.
By Frank Martin DiMeglio
I would love to take physics with Professor Lewin! These are the best lectures.
+RUclipsExplorer :) :) :)
I'm only 16:26 into the lecture, so apologies if it's answered later, or if I missed it.. but isn't the "one over R squared law" missing a whole bunch of factors? Like the gravitational pull from nearby masses OTHER than the sun?
Good teacher
Dalton Landis That is why a was proportional to 1 / R^2, and not equal. There is a proportionality sign, not the equal sign. If you add the extra factors it becomes equal.
Well I guess you are in a sense
Walter Lewin is the best physics teacher there is! He truly preserves and motivates me even more for my love of physics, maths, and most of all the love of scientific pursuit!!!
I'm an undergraduate physics and math student taking some higher level courses right now and I really enjoy watching your videos because it really helps drive the concepts beyond just the mathematics. It also reminds me, when I'm frustrated, why I joined the major in the first place and not to give up. You are an incredible teacher and I thank you for sharing all of this knowledge with us.
1. Excellent demos.
2. Very thoroughly explained, whereby anyone can understand the concept!!!!
thank you
you are welcome. I am high school physics and biology teacher. I find your lectures (where applicable to my lesson) very useful.
I am from Assam, India aged almost 40 and now I have realised to the core of my heart that I have not learnt physics at all though I work as a government service engineer thanks to the education systems/scoring systems we have back here in India. I pledged to myself I will learn atleast all the fundamental concepts of physics before I die as it is so fascinating & so close to the nature around us- Measurements with understanding of degree of uncertainty 😊- Thank you prof. hopefully you and HC Verma sir would make my life's next few years a fascinating journey
I haven't been so engaged in the physics lecture as much as I have been watching this video. Absolutely fascinating!
just another example of why MIT is the greatest University in the world... Professor Lewin performs a dry run of each lecture twice to an empty classroom before he goes on "live". ever notice how he never needs to pause to collect his thoughts? That he never repeats himself? THE BEST ...
Man I wish I've binge watch these lectures when I was learning this on college. Instead we just solve practice problems through memorizing these equations without getting a feel of what it really meant. Thank you for this lecture
I must say, what a wonderful lecture. While I may not have had the chance to attend MIT in the late '90s, these videos have provided me with an incredible opportunity to learn, almost as if I haven't missed out on anything at all. Walter, you're truly changing the world in a quantum realm, overcoming barriers that would typically determine who gets educational opportunities based on factors like geography, race, finances, and social status. In this quantum realm, it's akin to winning a lottery. Your work showcases that you're an eternal being capable of exerting control beyond our comprehension of space-time, and that's truly amazing.
The simple explanation is that our works is just like that with each victory giving us the ability to reach further forward and further backward; that means this is nice and all but we need to pick up the pace if we ever want to complete our goals and enjoy the our life forward in eternity
thanks for your kind words
Always a great lecture. Cirurgical precision. And it’s not negotiable! Thank u for the masterpiece of of your entire career.
My pleasure!
Words are inadequate to express my joy for your help.
:)
I never feel bored in your class sir. You are just awesome 😃
Glad to hear that
@@lecturesbywalterlewin.they9259 Sir is there any entrance exam for getting into MITs and if yes then , are those exams tougher than jee advanced ?
@@shauryasaxena7791 Yeah SAT. Its easier than Jee.
@@shauryasaxena7791 none is tougher than jee advance and mit don't have specific exam nowadays
@@overthinker69069 well yes and also the gaokao exam
I'm a indian and i love the way you teach physics..
thank you so much for helping us
Ultimate physics teacher with real life (example)stunts in hand. We miss you sir! but we follow your lectures🤘
All the best
I'm a 71-year-old semi-retired university psychology professor and I spend hours watching Dr. Lewin's lectures. Fascinating, absolutely fascinating.
So why you want to learn physics
@@ManojKumar-cj7oj he's not even eligible for jee now
MANOJ KUMAR professors of different disciplines love to watch each other teach. I am an artist and I love watching tutorials on maths, physics, and other science.
Hey!! It's all about passion age doesn't matter and you don't learn physics only for JEE it has more dept then that.'
@@toukatouka5768 vinayak no one here is for jee and nor do americans know what jee is in fact people are here for ap for some good college like MIT
Being a Physics faculty i had drawn a lot of inspiration from you professor.
SIR CAN I CRACK NEET PHYSCIS BY WALTER LEWIN SIR
Great teacher , whoever attend his lectures at the time was really lucky , worth every second of a life time
That's why as a pilot I experience the gravity towards my feet when I do a tight turn (coordinated of course). Great lecture!
the basic idea behind centrifuge just blew my mind.
It was like.... I mean..oh god! I can't express it!
Nothing is as good as physics prof... thanks for making us understand everything so easily 🙏🏻
Professor Lewin is Best teacher on RUclips ❤️❤️🔝🔝👌👍 love respect from india
I knew this was old but it took a long time for it to hit me that this was before Pluto was demoted from a planet in 2006. Wow.
Respected Walter sir , I am proud of you that my physics teacher recommends you and he teaches us after seeing your lectures🙏🙏🙏🙏
Your grandmother is really awesome...🙏
Love his elucidation... It's divine❤❤❤
I've been trying to find a decent class lecture on this for so long. Thank you, it's been very helpful.
Hi Sir! I'm in 12th standard preparing for JEE Advanced and am extremely fascinated by the way you teach. Thank you very much for these amazing lectures.
Bro how is your prep going
most inspiring teacher ever! thank you Mr.Lewin for still inspiring us.
Very few teachers are able to make physics meaningful and interesting..
Thank you Sir❤️
So FASCINATING😍. I love this guys lectures.
Sir the way you explain different topics no one can forget for life time
I really feel that if I could attain your class in front it would have been amazing
So nice of you
@@lecturesbywalterlewin.they9259 THANK You So Much Sir
How a man can be a physics teacher and not boring?❤️, love from Pakistan.
Sir, you save the lives of physics students everyday! I want to simply thank you.
:)
I literaally have tears in my eyes Are these type of professors of physics belong to this world?No words just thank you so much professor
His lectures have an awesome flow, love them.
I'm fortunate to have access to your lectures SIR...IM NOT IN REGRET THOUGH IM 60 YEARS NOW....I ADMIRE AT YOU AND TRY TO LEARN AND UNDERSTAND WHICH MAKES ME HAPPY...ALSO NOW I UNDERSTAND HOW GREAT UNIVERSITIES GET THEIR STATUS.... 🙏🙏🙏🙏PLK
How many lucky students are sitting. I wish our teachers were like this
Our teachers only disappoint us and ruin our future.
Open chested Salute to you Sir 🙏
Lots of love and Thanks from India 🇮🇳❣️🇮🇳
10:31 legend
ruclips.net/video/raurl4s0pjU/видео.html
that's actually pretty simple to do
@@nabhchandra_ not for every one
hi sir i am prepairing for neet and your lectures help me a lot
I was so dumb , few months back my mentality for physics was not like today. Thanku so much sir Lewin ❤️😇
I used to hate physics but after watching your lectures professor I have become the best at physics and now it’s my favorite❤️thank you for your hard work
19:00 absolutely genius!
I am jealous!!....WHY AM I NOT HAVING SUCH A GREAT TEACHER😭😭😭...Thank you for this Channel..Thank you Sir😃👏👍
You are very welcome
Great..excellent..all are very small word for you.
You are unique, thank you sir.
Hi Sir, I'm preparing for JEE Mains and Most physics lectures on youtube focus on problem solving rather than concept clearity and that's why I'm watching your lectures and now they made me mad in love for Physics .Thanks Professor Lewin ❤
Everytime I am heartbroken i watch this lecture. I dont know why but thiss calms me.
I have watched this 17times by now❤️
The best part about your lectures are your demonstration of experiments.
Like I had studied everything about those centrifuge and buckets of water and got bored with those diagrams and eqns😕 but today when you actually showed the experiments, I was like it's damn fun. 🤩
Thank you! I love learning from the best! What a world we live in to have this opportunity!
Wow what a lecture ⚡😘
Whatta lecturer💫
Never understood any physics this better.
Thank you Dr. Lewin
:)
Hi sir I’m a class 11 jee student too and I find these lectures really helpful as in coaching we mostly spend all our time on ways of solving problems and never get to appreciate the beauty being the topic and the subject. You classes really make me understand why thing happens and make me love physics which I turn helps me solve problems too! And I wanted to thank you for that . Also I wanted to know which text book you were using during the lecture
Thanks for providing all these amazing experiments for free.
Sir you always have a unique way in your every lectures, I HAD JUST FALLEN IN LOVE WITH PHYSICS because of you.
Thanks 😊
Perfect explanations! Thank you from Israel..! (:
Allah hu akbar
This is a far better resource than oxford textbooks, no mistakes in these videos!
Is there any way I can become professor of physics at MIT. I mean what must be qualifications to get job of teacher at MIT.
first get a PhD in Physics in the very best Univ that will accept you. Then get a postdoc position at a major University and make a name for yourself in doing fundamental research which the world will pay attention to. Then apply for a Professorship at MIT when they publish that they have an opening.
Lectures by Walter Lewin. They will make you ♥ Physics. I am a undergraduate student and i want to become a teacher just like you...I want to share my knowledge. ..views on physics. .....thank you sir for these videos
:)
wow .. good luck
Soooooo Hard but good luck 👍🏼👍🏼👍🏼
Just fell in love with your teaching sir ❤️ just great
I already love phyics❤️ 😉
2:13
Did anyone notice a fluctuation in 'T'
Omega=2π/T
This 'T'
???😱😱
Sir these lectures are fantastic as you get to learn the concepts in a better way, using real life examples and experimentations. Thank you for such an assistance.
Hi, and thank you.
Ramiro Gonzalez hi
i cant explain when i understand each and every thing with your experiments and with your teaching the satisfaction it gave me is just amazing i never understand physics so beautifully
Sir you are the epitome for love towards physics ❤️ I respect you.
very clear sir
thank you very much
but I want to ask you A question
How can we study the relationship between centrepital acceleration and radius
is it always linear?
At any point in time, t, there is an centripetal force on an object which is mv^2/R. v is the speed at time t, R is 1/"curvature" at time t. The direction of the force is perpendicular to its velocity (it's pointing towards the center of an "imagined" circle. The centripetal force is ONLY zero if the object moves along a straight line as R is then infinity.
no centripetal acceleration is inverse with radius BUT ONLY IF the tanget speed is the same for ex: if you're driving a car at 34m/s and try to take a 24 meter radius turn your acceleration would equal 48m/s^2 according to a=v^2/r,
and if you try to take a 33 meter turn at the same speed your acceleration would be 35m/s^2 .
42:08 Really helps me with minimum velocity for circular motion
i thought there was no thing as centrifugal force ...now you introduced that concept through perceived gravity ...now im confused???😲😲😕😵
+Bhoovesh Waran In My reference frame as I see something rotate in MY frame there is NO centrifugal force but there is a centripetal force. End of story. I cannot help you anymore. I NEVER even use the words centrifugal force in my lectures.
+Lectures by Walter Lewin. They will make you ♥ Physics. But how does gravity act outwards?
+Bhoovesh Waran I do not know what you mean by "outwards". I fear that your background in physics is insufficient to watch my lectures. I cannot help you any further. The grav acc is ALWAYS down. That's mother nature - we cannot change that. However, you may always choose what you call + and -- in your coordinate system. If you call vertically up +y, then grav acc pn an object is ALWAYS --g. If you call vertically up --y, then grav acc is always +g. The choice of signs does NOT affect in any way the physics. Good luck! .
+Bhoovesh Waran "perceived" gravity can be in any direction and it can change direction fast.
If an astronaut were in a fast rotating satellite, (s)he would perceive gravity (which is NOT real gravity) "outwards from the center of the circle of the rotation. The direction would change continuously radially outwards - 360 degrees in the period of the rotation. Since the frame of reference of the astronaut is the rotating frame of reference, astronaut (s) will "experience" a centrifugal force (outwards).
I liked the way Indians are getting this video recommended thanks sir and youtube.
Imagine having your sleeping quarters in the middle of a wheel :0
Sir u r the best teacher so i m here to study for jee advanced from u
Thanks for providing one of the best lectures sir it's an honor to watch this lecture
Professor, is there any scholarship exam that I can apply for to study at MIT?
How to get into MIT?
ruclips.net/video/hRp3ND-fBNw/видео.html
SAT Scores and GPA (www.prepscholar.com/sat/s/colleges/MIT-SAT-scores-GPA)
The average GPA at MIT is 4.13. This makes MIT Extremely Competitive for GPAs.
The average SAT score composite at MIT is a 2220 on the old 2400 SAT scale.
On the new 1600 SAT, this corresponds to an average SAT score of 1520.
Hi, Professor Lewins I am preparing for my NEET exam and your lectures are helping me a lot in Physics.
Respect 🗿.
That's great!
"Lettuce fill this with water..." hehehehehehe
I see what you did there.
His lectures are simple ,he is simple yet they are the best.
Professor, I am curious to know more about the gravity you mentioned at 45:00
Is that what some people mistakenly attribute "Centrifugal Force" to? Also, does the person being swung around experience such a (perceived) gravity because of Newton's Third Law of Equal and Opposite Reactions? As in, when there is a tension force pulling downwards on the person, the person experiences a force in the opposite direction?
Thank you!
The person who swings around experiences a centrifugal force that pushes him outwards, but the string or the rotating platform will keep him in place. Thus the person perceives gravity outwards
Thank you for your answer.
Follow up: Does that mean you would draw a centrifugal force in a force body diagram of the person being swung around?
If I am outside and I drew a free body diagram there would be only 1 force (the centripetal force pointing to the center of the circle). If the person on the centrifuge would draw a free body diagram he would draw 2 forces: the centrifugal force radially outwards and the force that the wall exerts on him. This force has the same magnitude but it is in opposite direction so that the net force on the person is ZERO.
It depends on your frame of reference. Read my earlier msg
Lectures by Walter Lewin. They will make you ♥ Physics. Hi friend take an object and make it go circular motion then in the free body diagram of that object u will draw only centripetal force towards the centre . Now u sit on that object then u will experience centrifugal force ...
You made physics easier sir.
Love & Respect from Bangladesh 🇧🇩
sir i am from India in class 11th and preparing for IIT JEE your lecture is so helpful to me and also i am student of Physics Wallah and lots of love to you for this kind of lecture
Grateful to have his lectures free of cost. Thank you sir.
This is just a fantastic series of lectures. Professor Lewin why couldnt you have taught me physics in school!
is there connection between physics and chemistry
YES, use google
Lectures by Walter Lewin. They will make you ♥ Physics. ok
:)
Definitely YES ! The best example is THERMODYNAMICS .
Chemistry is just applied physics.
When sir demonstrated about the angular acc. of planets on the logarithmic graph sheet ,and showed how it forms a straight line ,my curiosity went passed pluto's orbit.
Thank you very much sir, for giving me this whole new perspective about physics ❤️.
I am from india grand pa , i found beauty of physics from u
And im preparating for jee ur videos give me confidence and sparks ❤️
In biochemistry the ultracentrifuge is used to separate molecules. These reach one million gravities. The material in the tubes experiences an acceleration of 9 800 000 meters per second. The goal is to separate molecules into different layers based on their difference in weight. Typically this difference is 0.000 000 000 000 000 001 grams.
The Zippe-type centrifuge is a gas centrifuge designed to enrich the rare fissile isotope uranium-235 (235U) from the mixture of isotopes found in naturally occurring uranium compounds. The isotopic separation is based on the slight difference in mass of the isotopes.
I have no idea why I'm here. I'm only in 6th grade and this makes no sense.
you might as well enjoy it!
Sir your video is very amazing and very helpful for us I am preparing for neet 2025 ❤
Thank you so much
Thank you professor Lewin for such beautiful sessions.
Much information given by walter Lewin. Sir nd i hav cmplted some lecture b4 8yr so i m now stdying nd teaching the Physics..
Coming back to this lecture for a second time now, I've just started doing a course in classical mechanics at a swedish university. We actually have lecture for the course as well, but the lecture for UCM was only 13 minutes. So I was gonna come back to see that derivation that you spoke of but I had forgotten that you left that for the student to read up on 😆. But I will watch the lecture again regardless since I just love the performances you put on back in those years they were recorded .
Hi, Professor.
First, I would like to thank fot these amazing lectures. An immortal legacy whichhas been fascinating whole generations over the years and it will continue doing it, I hope, for always and forever. I´m enginner, I have learnt classical mechanics at schools to a, we could say, a middle level in comparison with a physicist. With your extremely didqctic lectures, combined with Lectures on Physics from Richard Feynman and the classical analytical mechanics of Suskind you are making my work free moments.
I would like to know your opinion about this hipothecial physic situation: If the Sun would suddenly dissapear, the effects of lack of gravity would be felt immediately or these would travel at light speed and the Earth would wait for the respectives 8 minutes to tqke off in a straight line?
If you can`t find idle time or motivation enough to answer this question, just don't feel bad at all, I understand you have lots of questions and followers sollicitating you as well. I just try my luck.
Thank you in advance.
It would take 8 minutes before people on Earth would not see the sun anymore and the Earth would then no longer continue to be in orbit around the sun.
@@lecturesbywalterlewin.they9259 I really appreciate your reactivity, thank you for answering me. It's an incredible honor for me. Take care !
Lots of respect for the legend of physics #Walter lewin Sir from #INDIA 🙏🙏🙏🙏
as usual amazing lectures by professor! at around the 10 min mark, when you are discussing about the trajectory of the ball when the string/pull is cut; the way i understand this is by imagining shot put players. they do a spinning motion but in the end the ball travels straight!
Moving toward the sleeping quarters will cause that 30 m/s to be reduced linearly to zero at the center causing a Coriolis force pushing you into the wall of the corridor in such a way that you could almost walk to the center. The faster you went toward the center, the more traction you would have compared to the centrifugal effect trying to sling you out.
At 11:22 , I think for the time sound takes to travel to the ball it would keep going in circles...