The fact that you take an active role in your channel is one of the coolest things there is! Thank you for your work!

I so enjoy your lectures and your love of the material. I have to watch it more than once and that is one of the joys. Thank you. raphael santore

Sir I am a 11th grade student from India....your lectures are so awesome. The experiments you do really help getting the feel of what we usually study as exhaustive theory and derivations. The lectures really do make you fall in love with physics!

The old good times, when U-tube meant just a a U-tube....:)

I have been watching your lectures since 2014 when I took master degree in science education and focused on physic education. I have got deeper of understanding physic for teaching my senior high school students by watching your teaching methods. very much helping me and awesome. thank you very much sir,,, from Indonesia

I wanted to thank you sir. Your lectures really help in grasping the important concepts. I was facing trouble in understanding this concept. Now it is better :)

look this over again when i take signal processing course , still impressive and valuable thanks sir ^^ together with lesson 10 so neat , in depth, amazing , so great to have you

Hello, Walter Lewin. Which science (physics or astronomy) book do you recommend me? (The style of 'A Brief History of Time'; 'Cosmos'; 'The Grand Design'). I'm learning how Nature works. So I want your recommendation of a science book. Thank you.

Professor has very elegant handwriting and sketch intuitive. He always has interesting demo for his theory. I wish I could have attended his lecture.

4:33 In Rod we trust!

Are you utilizing the chain rule or the product rule?

In that tube experiment, why don't you consider the air pressure?

Hi professor, i think i found my mistake, to find the work of the force with which i had to push down the liquid at the left side of the tube so that the liquid would raise up on the opposite side, i incorrectly assumed that the force was constant for all the delta h and equal to the force with which i had to maintain the equilibrium at the end, just like if i had to lift a rigid body with fixed mass, but then i noticed that for every dh the force would raise up proportionally with h, that's because the unbalanced mass in the system gets bigger and bigger the further I go down pushing, so the work would be (integral)--->S(rho)*Area*2h*g*dh, and not 2dMgy as i incorrectly assumed, the result of the integral is dMgy and not as i said before. If i could correct my error I owe it only to you professor, have a good day, greetings from italy!!

Hi Walter Lewin, i am really grateful for all the lectures of yours that are on internet for us to see. I watch your videos everyday and it's always interesting and awesome. I am a high school student studying Alevel in Nepal and these lectures helps me a lot to learn beyond our syllabus and for my own exams. Thankyou so much !!

Hi, I have a question about the assigment 8 ,8.4, c). The formula i got for r1/r2 (r1/r2=x) was : x+2x^2+x^3= (M*G/V^2*r2) = 0.53. But in the answer sheet it says it equals to 15.9 and I´m not sure what I´m doing wrong. Is this equation correct : x+2x^2+x^3= (M*G/V^2*r2)?

Why should L have been longer in the liquid oscillation experiment?

Hi Prof, @24:25 when the water moves up on the right side of the u-tube, is there any loss of potential energy on the left side, since the water falls below the U=0 level?

were questions prohibited during the lecture or they were cut out?

26:20 Can we Do this with Bernoulli's theorem

Professor I suppose that the 'l' @ 30:00 1. must be taken from the middle of the pipe OR 2.We can add the vertical parts of the pipe and then find the mass of fluid in the curved part by doing an integral over using small mass elements 'dm' is that correct professor?

Sir, I have seen all of your lectures in 8.01x I want to ask that can I see lectures in 8.03 by skipping 8.02 or seeing 8.02 first is a must ?.

Dr.Lewin, I just want to prove that the actual “l” should have been taken a little bit larger than π(r1+r2)/2.(I only consider the bottom torus).r1 is the inner radius and r2 is the outer radius.I used integration to calculate the volume of a torus.But amazingly I got that the volume of torus is exactly equal to (π^2)*(r1+r2)a^2 =2A*l.So the bottom half of torus should have volume =A*l.I uses 3 different methods to calculate that and they all give me the same result. Can you explain me why l should have been taken a little bit larger.

"l" in the differential eqn is taken as the displacement of the centre of mass of the displaced liquid, which will be higher than the "l" we get if we take the average of the two radii and measure it. Is this correct?

At 30:00 you said L must be little bit larger then it's actual value. I think that's because of the thermal expansion of the liquid. Because when liquid will oscillate it's will loose some of it's energy due to viscosity (which will cause Damping) and that energy will be converted to heat, which will cause thermal expansion. Area is constant here, so the only thing that can change is the length of liquid column (This will give a tiny increase in volume also. ). I think that's the reason for L to be a bit larger.

hello professor, at 25:19 you show that dM*g*y is the work of the force, shouldn't the amount of unbalanced mass be 2dM? and so the work would be 2dM*g*y

In the HW the astronaut ends up with negative blood pressure in the brain. What does this mean?

Sir, around 30:00 mins in the lecture you said that we haven't taken 'l' accurately , why is that ?or in other words why the value of 'l' should be a bit larger ?

At 36:38, the torsional constant kappa has a more interesting dependence on area, than just the number of square millimeters. The concept that matters is second polar moment of area, defined in a similar manner as moment of inertia. The essential difference is that density is dropped from the integral.

Professor.. what's your favourite experiment? :)

Hey do you know Dianna Cowern? AKA Physics Girl?

If a tunnel is made through the centre of Earth, along an entire diameter, And, If an object is released at one end of the tunnel, Is it true that the object will be in Simple Harmonic Motion ?

Hi Professor. In this lecture (22:55 min.) u mention that vellocity will be same for any moment in time due to cross section area of tube is not changing. But will it same or it will change by the time? Because derivative of (y) includes (t) and it is logical due to gravity. i think i misunderstood something or not? Thanks.

Sir, did the string broke? What was the summary of the tortional strain experiment?

Sir, can you please tell the answer of 30:00 question... I'm having sleepless night due to this question. But till now I didn't figure out the answer. It will be great if you please explain the answer. Thank you so much sir. Love from India ❤️.

Sir we love your videos , the very brilliance of your teaching does not let us lose our focus even once . Thank you so much for all of it as it makes the concepts crystal clear and easy to understand. ( at 36:41 though , the Mung's-Young's modulus is just memorable)

Hello Professor Can u please tell me about the concept of centre of percussion in such physical pendulums please?? And thanks for your fantastic lectures

Professor, I've notived that when measuring the torsion pendulum oscilation, when it was given 10 initial turns, the first full oscilation consisted of 17 turns instead of 20, and the second one, the one you actually measured the period of, consisted of only 13 turns. My guess is that there was permanent deformation that did not affect the period of oscilations, but the angle swept by the pendulum

I didn't know that glow in the dark chalk existed until 31:21

Dear professor, at 26:00 why are we adding potencial energy, i know in problems with conservation of energy (for example) its always mgh=(m*v^2)/2 so if we put mgh on the right side it will be negative, and in your case potencial energy has plus sign, why is that?

Why should L be a bit larger? at 32:10 you mention it, but I see no reason as to why it should be larger.

Sir please reply me . I am a huge fan of yours

When the length of second pendulum becomes four times what z the perid then???plz

Can Circular Motion be considered as SHM?

I am from India And I read this is class 11 Our education system is broken

21:10 , To resume tomorrow

"We have here a U-Tube..." Prophetic? lol. 😅 -G-Force

Sir, you said that any measurement without the knowledge of uncertainty is meaningless but some of the lectures at the later half of 8.01 you have not taken uncertainty into account. Why?

Wow

Wat meaning of double dot theta

good evening proffesor .... I'm purva and I'm a science student preparing for the iit jee examination in 2017 ( considered the most difficult exam for sciences ) my syllabus is much vast than just what discussed about in the lectures..... is it possible to get help from you even beyond this syllabus . I mean can I contact you somewhere else if you are ready to help me out .... it will be really kind of you if you agree to help me ....hoping for a positive reply ....thank you very much .

I feel the lecture was incomplete. It ended abruptly

Hi guys! I wanna thank you first for the amazing videos. However, I think we must take the moment of inertia of the bar into consideration while calculating the moment of inertia of the whole system (bar + 2 masses) . I'de appreciate it if you tell me why Mr Lewin didn't do so! :)

sir please bring lectures for chem and maths plzzzzzzzzzzzzz......love from INDIA🙏🙏🙏

i have seen a beautiful girl in most of your lectures ,in this lecture she was in black top (42:42) but nevertheless she is not more beautiful than your lectures and experiments.

U-tube lolol

You tube