Lec 19 | 8.01 Physics I: Classical Mechanics, Fall 1999

[murmurrer]

the dotted lines, its awesome!

[wwesonyfan]

Jesus Christ! Am I going to have professors like this when i reach college?

[bebeheuy]

I am very happy to see the vidoe after you give this Rotating Rigid Bodies - Moment of Inertia - Parallel Axis and Perpendicular Axis Theorem - Rotational Kinetic Energy - Fly Wheels - Neutron Stars - Pulsars

[AntoMelta]

I Really Like The Video From Your Rotating Rigid Bodies - Moment of Inertia - Parallel Axis and Perpendicular Axis Theorem - Rotational Kinetic Energy - Fly Wheels - Neutron Stars - Pulsars

[willamricard]

Your Video Is Very Useful Sharing Rotating Rigid Bodies - Moment of Inertia - Parallel Axis and Perpendicular Axis Theorem - Rotational Kinetic Energy - Fly Wheels - Neutron Stars - Pulsars

[imegatrone]

after i watched this video Rotating Rigid Bodies - Moment of Inertia - Parallel Axis and Perpendicular Axis Theorem - Rotational Kinetic Energy - Fly Wheels - Neutron Stars - Pulsars, my insight is very open because the video is very good to give information

[FreakySpookyCat]

Wow ...Is that the serbian's vest(called jelek)?

btw..great lessons...!!!

[eldokch911]

how can you draw an imaginary line this fast you just pass that white thing and it draw points on its own

[liveyourlife123able]

you are boring !!!

[flipp500]

Most awesome vest ever....

[dirtyharry609]

How about a magnet that harnesses kinetic energy from its self ??....but with nuclear power and atmospheric

[mufc4everch]

This man is awesome, but what's with the vest....?

[wolterh6]

he is a god at making dotted lines lol

[huggy406]

some of the students in this video probably went into the development of hybrid autos.

[mdgreg]

Does he "Ride" his Brake, In his Car?

[mdgreg]

I Think this is Basic to Our Common Experience, Basic to Our Interaction.

[purpleleach1]

Can I ask why the optical picture of the Crab Nebula has been removed from this video?

[cyrozap]

@purpleleach1 Probably to avoid violating copyright laws.

[theforestero]

earth needs blue physics to help primitive eath minds.

[flashsnipe24]

this word be awesome if i was one of those people who had a photographic memory

[alissandrodionysus]

A car travels 210 miles along the turnpike in 3 hours. How fast was that car going?

[alissandrodionysus]

@alissandrodionysus I wonder could someone tell me if this is the right answer. to this question v = s_t = 210miles_3h = 70m/h. The underscore is the same as the dividing symbol.

[plusafdotcom]

@alissandrodionysus .... counting time for the police to stop it and issue the ticket?  average speed might be 70 mph, but counting the speed trap, it must have been higher.

you couldn't figure that out yourself?

:)

[sssss3841]

28:55 quick change of voice 0.o

[ssa09003]

Wait... why is the angular velocity along the direction of rotation?.. Shouldn't it be in the upward direction according to the right hand grip rule?

[mattalessi2112]

@ssa09003 velocity is the direction of a particle on the circumference, or along the direction of rotation. You're right, angular velocity follows right hand rule. But a lot of profs when teaching on a blackboard just use clockwise/ counterclockwise because it's easier for everyone to follow than into/ out of the board.

[meisje92]

Tables? Seriously? We have to do the integral to find the moment of inertia at my uni. Great.

[FloOFy2]

At the beginning, does anyone know what the dots are on top?

[Nicoida]

@FloOFy2 It's a derivative with respect to time, so for example when he writes "theta dot" it means the same as

d theta / d t

[OTSPProductions]

@FloOFy2 hes just signaling that they are derivatives of that specific symbol, so one dot is the first derivative and two is the second

[TheTalhanisar]

Hi! I am B.S student. Have you lectures on optics, waves, and SHM?

[TheHeretor]

thank go i didn't take physics 

[65051088]

He should teach online classes for my school ........ BRILLIANT

[Mike50040]

Wow what a great explanation of the moment of inertia! This has been taught to me in a couple of classes, but its always been this big confusing thing that everybody memorizes. Never seen it taught with such clarity!

[Tinak00777]

O____O;

[TheShideh8]

SOMETIMES I WISH MY TEACHERS WOULD RIGHT JUST AS BIG ON THE BOARD

[illPerspectives]

hmmm yes yes, i took one step above the lowest math...needless to say, the second the chalk touched the board i was lost hahaha

[Cifrocco]

That vest is too distracting, I can't concentrate on the lesson, lol.

[moussaouiahmed]

vous voiyé mes amie ce zero qui eté absent de vous memoire est plains des criation .mes je vous le reservé la foulus de l energies guratwi est un foulu zodiak est transpore de la joiax quent vous me visité au maroc merci

[MrSoccerFan096]

my fucken physics teacher brought me to this vid -___-

[inali3]

Yeah, that classroom is about empty. It's a shame with such a high caliber professor that actually makes the subject material interesting. My physics class is packed full, with a prof that attempts to put us to sleep. I'm so jealous

[SwiftCuber]

Damn inertia. Just how would Pure Maths do wonders to prove those moment of inertia for different cases?!

[ZarMulix]

@SwiftCuber Something similar to calculating the distance from the center of mass for each geometric point and integrating it. I had some problems in my physics class about it but never understood it fully (I suck at math).

[SwiftCuber]

@ZarMulix - Oh right! The name "Integration" sounds complex that I forgot how simple calculus is. Anyway, yeah I agree. It's just about the volume stuff from a function (Rotation about axis). Thanks!

[eggie545]

SOO good

[allantapps]

NICE VEST LOL PART TIME BULL FIGHTER



[elvisjrsinfo]

Wonderful.. makes my spelling look much better .. My stomach is turning though? I have to hold somethink- I am spinninng.. I taking cooking..?

[chrisig0]

in other words: 2 + 2 = Fish

[65spiders]

i have no clue whats going on but i think his chalk board skills are amazing. good work.

[airmax247]

60968 people don't undestand this.

[ironstealer87]

@airmax247 Its actually more than that.

[twistedhand86]

he makes engineering course looks less scary..kudos to him...

[filipeaa320]

His classes are wonderful, and it's so sad to see that there are so many empty seats there....=(

[Ad23051958]

outstanding physicist and teacher. the lectures should be made available in dvds internationally

[volimzube]

wow! was this physics?

[Saiien3]

@volimzube Its actualy called Mechanics, but its a three of Physics.

[gimbochi]

how does he draw those dot-lines without screeching on the board?

[albaz7pc654321]

I am a physics teacher... But i hope to be like him.

[Parshand]

he's my favourite teacher and i've never even seen him lol

wish i'd b able to meet him and sit in his class

science the way I was being taught was getting so boring and stupid

had forgotten why i ever liked it in the first place

This guy is the only reason i am studying again

[darkoriginhunter]

man that vest is cool

[zackalphaomega]

too fast

[mandy1339]

Holy Crap this was way too interesting

[Nightdriver61]

I know that as humans we are headed to very very great awakenings.Our days and life's in space is happening now,so cool.

[coolestdude80]

That is so redundant!

[tobiasohz]

I dont get it!

[corneliaomir]

@tobiasohz If Professor Lewin can't make you get it, then you must stop trying to, because is not going to happen

[mornmeril]

This is amazing - I am a humanist, majored in history and literature. I do not understand a word he is saying (alright, I know SOME of these from high school), and yet I listen to this lecture because it is very interesting. I believe this is a mark of a good professor.

[SealSquasher]

@mornmeril

Agreed. I am more into sports sience, haven't studied physics too much. It's also very very late (0115am) and I'm a stupid Finn so I dont handle english too well. But still I find these vids interesting :D

[LogicalFlawDetector]

@mornmeril

You can understand what he says just by viewing this series from the beginning. Taking notes will substantially help you understand. 

[rokhanmang]

What a rare opportunity.. thanks for posting these lectures.

[whatelse041]

he's Dutch, the professor, I recognise his accent.

Nice Lecture, thanks for uploading :)

[chiefthegreat]

Why did some asshole remove the crab-nebula-picture from the video ?

It was taken by equipment, paid for by tax-$; it should be there !

[Zeldakitteh]

Silly American, not everyone watching this pays money to America. ;P

[chiefthegreat]

Ah yeah ... If at all it was taken by american equipment ... ...; much of science is internationally funded ....

Also: With the current indebtation of the US (somewhere cabove 10E12 $), again the rest of the world would have paid for it anyhow ...

[plusafdotcom]

@chiefthegreat .... and they couldn't find a non-copyright image? somebody's a moron somewhere on that one...

[CoolGurjot]

All u peplz, v r here to explore concepts of physics and not to design his clothes, so better listen attentively and dont watch his clothes

[theLichKing1]

who cares about the jacket.. this is a physics video

[amrosik]

aside from that it looks good.

[excursustoo]

Thanks for this.

[katsmiles123456789]

the jacket is part of the secret astro physics uniform

[erz2010]

@katsmiles123456789 the jacket looks so alike some traditional clothes of my country Albania usually its a women clothe.. and I was certainly very surprised when I saw him wearing it :O

[nops11]

What is this jacket?

[philosiphy]

your so fucking stupid.... haha obviously. Why do i even have to tell you? u probably know already nops11

[nops11]

i am not stupid. stupid is probably you, because you not understand that not all people is native english.

What is the type of jacket on lector?

[brilliantdiamonds]

About the jacket:

The best i can do is tell you that the large knot on the back is a classic simple celtic knot, but i have also seen it in ancient African textiles.

Maybe it's something made for tourists? or maybe it's just a costume from a christmas play that he decided to wear?

He wears some wacky stuff; he's got a shirt pin that looks like a fried egg.

Sorry, I can't be of more help.

[OkazakiMasamune]

how does he draw the dotted lines so fast?!

cool video though

[yogiudo]

battery powered chalk.

No, not kidding.

It has a button on the chalk holder which makes it vibrate.

[lutinblanc]

Actually I'm pretty sure he it's just the way he presses the chalk against the board which causes the chalk to vibrate

[hamtr3]

there is a ring around the outside of the chalk with a slightly larger one around it. Its like a bearing and the chalk is the axle.

[komm1981]

that is an example of limited modeling with a car and a disk.

that would be fine if you model it on a flat surface, but since it is from downhill to up hill then theory of Gyroscope shall be used, and you will have to spend that much energy that you store to change the angle of "Gyroscope" rotation. That is why we dont use this kind of accumulators in cars, because the disk has to weight proportionaly to the speed of disk rotation.

for more information see ie wikipedia

[jurisnake8]

Prometheus4096:

Do you know examples where it works well?

[Flatline89]

Lol "in the next decade energy in cars could be stored", it's 2009 now, and look, it's happened lol

[ggggg1234323]

KERS in F1

[coolestdude80]

This guy is awsome!

[666j1]

the vest is very stylish, also he has a dutch accent , is he dutch/belgian?

[butterbat]

Yes, he is Dutch.

[Avogadro1988]

yeah he is definitely DUTCH! i went to school in holland so i know a dutch accent when i see it

[mohamedsupzero]

fantastic

[nhojmabon]

This has really puzzled me, does anybody know how walter makes the dotted lines using the chalk?

[941254]

He applies different magnitudes of pressure.

To make a line he applies lots of pressure.

TO make the dotted lines he applies less force.

[nhojmabon]

Thankyou 941254

[Ladarzak]

@nhojmabon Like the person below implies, to do this you don't press so hard on the chalk, and you also hold it tightly and at a slight angle, so as you push it skips, like a rock on water. Low angle.

[summerday44]

if the fast rotating wheels rotate a larger wheel, it will give it more torque in opposite direction

[Dweirdo12]

best prof ever!! one day i will be a prof in MIT as well :D

[kristiankroflin]

This kind of physics is like the relation of Linux or DOS to Windows: there´s not much visuality but a lot of text. Half of both would be the best solution.

[summerday44]

well i think unless you go to the deep level of physics all you have is lot of equations. then in higher books you will see little equations because then you are able to be secific and lot of graphs and essays.

[kristiankroflin]

So it´s the same as the evolution of command line Operating Systems to those with GUIs.

Your answer sounds plausible to me. Thank you.

[tr1ptan]

Most professors I've had are good at drawing dotted lines, just because they do it so much.

But this guy is fucking insane.

He's the Jimi Hendrix of chalkboards.

Just look at those freehand circles!

[basurero123]

Even I tought he has a kind of curious tool to make the doted lines.

[jurisnake8]

I use pretty much of these basics for my game-physic-engine.

[jurisnake8]

With seven years he bothered about energy waste? As kid I bothered and made theories how to beat the bike-level in battle-toads, lol.

The problem with the flying wheel is that if your car is climbing up a mountain using the same equations you will waste exactly the same amount which you stored, lol.

[summerday44]

but if you rolled the fluywheel down and picked it uop at end and fixed to your car you can use it :D

but seriously you can use the potentiol energy of brakes in a spinh and release it

[troponinnutrition]

Everywhere where your real life involves these concepts.

[MrWakethesheeple]

Hey I agreed with your point of sarcasm. I guess most people viewing this are either putting on a front of intellectual supremacy or just have a better memory than your average bear and perhaps had better teachers.

[TheHuNTERplus]

I guess he's spanish :D

[xt4391]

Dutch, actually, but good guess.

[fatmanprime]

How's that a good guess?

He doesn't sound at all Spanish.

[kadukov]

damn, I wish HE was my physics prof.... he's not at all worried with the math involved in the formulas and stuff, in my class we have to discuss the proof of every single one of them, and we have exercises with rotating asymmetrical masses and ARGH! he made it without them, why can't i try? TToTT

[ytamel]

i love ur jacket

[michaelpaul513]

This guy is a boss, i love his vest. And this video is really helpful too.

[liveguns]

damn now you can learn this stuff for free.

of course you may not have the funding to use it. and the credentials to get a job but.

it is still awesome.

[shim2dawg]

guy makes sweet free hand circles

[kadukov]

and straight lines and arrows! And dotted lines, I find those particularly amazing xD wish I had such abilities!

[tachyon7777]

Why is that optical picture of the Crab Nebula removed from the video?

[kadukov]

probably copyright issues.

[AussieNate81]

I agree the vest is cool

[jonahansen]

Damn! Lewin is good!

[phengvue3]

wish I take this professor

[heaventreeofstars]

gah this guy is such a nice professor. great study tool.

[jaciel2001castro]

i dont think this dude is teaching still...just research...retired.

MIT source..

[vuuren007]

I will evan pay for his ticket tothe U.K can anyone tell me how to get in touch with him.

[liveguns]

lol yeah sure.

[vuuren007]

I need a guy like this to help me with my wheel.

[UNCsoccerL1]

sweet vest