Torque: Crash Course Physics #12

[@crashcourse]

We made quiz questions to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/3TW06aP

[@SnoozeTheRecluse]

I'm learning my whole semester in one day

[@phathumudau223]

"you know how physics loves ramps, especially hypothetical ramps" , please tell me something more true than this

[@aksharaa5376]

passive-aggressive physicists

[@DapaChrons]

the key to watching these videos is to pause to think on and rewatch certain moments if you don't grasp them immediately. These videos also help in conjunction with reading or other videos. I'm here because my physics textbook didn't explain what torque was but launched into a 15 page discussion of magnetic torque

[@pandacutiesuperstar]

Its not that she speaks too fast, its that they expect you to have a background in this, its like a review

[@pranavkulkarni1414]

The jump cuts don't help either.

[@gusbisbal9803]

I have a back ground in this and its treating the fundamentals like its something we can just skip over. Like the units of torque are crucial to understanding torque. ITS NOT A FORCE!!! is what it tells you. As soon as you say its not a force then the question of what is it really???? can be answered. Thats when you begin to understand it.

[@brontecharles]

@@gusbisbal9803 This is called CRASH COURSE FOR A REASON. SHES SUPPOSED TO HELP REVIEW THE BASIC TOPICS IF YOU WANT SOMEONE TO HOLD YOUR HAND AND WIPE YOUR NOSE FOR YOU, GO TO YOUR TEACHER OR KHAN ACADEMY

[@shreyaprakash]

For anyone watching Crash Coures physics for the first time: Dont get tensed by watching these videos.. These videos are best for reviewing the concepts after learning the topics beforehand.. They are not recommended for anyone who wants to learn these concepts afresh.. Dont freak out after watching these videos, it's fine!!

[@kikumayumi9219]

the whole point of crash courses is to get people an understanding of a subject, not to review it

[@shreyaprakash]

@@kikumayumi9219 Exactly! And that's what disappoints most of us watching the videos..

[@kikumayumi9219]

@@shreyaprakash how so does it disappoint us, this crash course was a great help for me when I watched it

[@shreyaprakash]

I think you must be having at least some basic understanding of these topics.. My point is that people who want to start learning physics or those who have no background knowledge of the subject will find it extremely hard to grasp the concept.. It's a generalized view..

[@xSkyHigh12]

I really like the way she... torque

[@caihui5697]

HAHAHA

[@enriquea96]

good one brah

[@marcelinatuszynska97]

OMG AHAHA. THIS SHOULD WE TOP COMMENT

[@enriquea96]

yes he definitely got me xD

[@wavinsouth7327]

loool

[@bootswiththefurr4718]

"Have you ever pulled a door open? Me too!" I love it. 1:04

[@NarekAvetisyan]

I understood none of this. But, I feel smarter after watching this video.

[@yasmeenhayat1378]

I actually really enjoy how this course is set up. It explains the basic concepts behind the equations so that when you go and practice the skills, you have a general idea on how to tackle them. I have to agree with the feedback others have given - you do whizz through the material. However, this medium can handle that, as you can just replay portions of the KZbin video. Keep up the good work!

[@SunriseFireberry]

The One Ring comes third, but it rules them all!

[@benaaronmusic]

...and my axe!

[@arcaderockstar7536]

RISE!

[@ricodelta1]

I have a cock ring

[@ddmagee57]

A male chicken ring?

[@pietrocelano23]

One Ring to rule them all, One Ring to find them,One Ring to bring them all and in the darkness bind them.

I have a degree in theoretical physics, and I just adore this series!

[@KingJokerRock]

A science lesson with a mario box, the one ring, and a dragon ball.... I'M IN!

[@mukundyadav4445]

KingJokerRock also the ring is from 'lord of the ring'🍻🔥

[@noabsolutelynot3660]

@@mukundyadav4445 that's why he said "the one ring" that's what it's called

[@biggbuck9535]

Should've used a power ring from Sonic the hedgehog. Then it would've moved faster down the ramp? 🤔 Lol

[@begonthotiana9487]

my kind of lesson

[@wakimaniac]

I slept through a physics class one time because I was tired, they explained torque. The teacher wouldn't explain it again. It's been two years, but now I finally understand this concept. Thank you so very much.

[@andersalexanderandersen5022]

These courses are pretty good for brushing up on - or repeating - physics classes, but I don't think they're very useful as a introduction to the subject. I understand that you need to solve problems to get to the core of physics, but listing a bunch of equations and explain their consequences isn't going going to give most of the audience a deeper understanding (this is an assumption!). I know the course would be taught in a much slower pace, but for really interested audience with a first hands experience, this is not building a solid foundation (in my opinion). I think it should be a blog post deriving all the equations displayed in the video for those who need a solid understanding of the equations. Don't take me wrong here, but I think this would please a bigger audience than the current setup.

[@FirstRisingSouI]

I agree. I think it would be better if the math were mentioned for reference, but the instruction kept mostly to the conceptual.

[@IoEstasCedonta]

I'm not sure how much more conceptual you can get than this...

[@AlbertoMartinez-rk2lf]

You may be right in some way, but in my opinion the most important thing is how cool is this vid so people like me, with no background in physics, take interest in this topics

[@Csilaverte]

I disagree. Most of the edutainment videos on KZbin are lacking the solid, somewhat rigorous aspect of that particular branch of science they currently teaches. These CC Physics videos do not: they have it in the form of the necessary math. The best thing about them that they serve not just as introductions, but also -as you have stated- help brushing up on previously attained knowledge, refreshing them. I'll write the exact same thing i am fond to say about this topic: if you are not interested in the nuances of mathematics, physics is propably not for you.

[@Mukation]

That's why it's called "crash course". It's not meant to be equal to an actual physics course in a school.

[@karanmehta5753]

to everyone saying that she is talking really fast.. that is because (if you haven't noticed) the channels name is called crash course and hence they have to explain topics quickly. I think that these videos are like reference materials that you can use to understand concepts quickly once you have a brief idea of the concepts.

[@cherri_tsuuuu]

now you know you should buy your future wife a box so you guys can have a smoother relationship

[@davet5223]

Don't forget to put the ring inside the box

[@zoeferrier858]

@@davet5223 Ayyyyy

[@sumitjha9730]

Thisvideojusttaughtmenottousespacebarwhenyouspeak.Thankyou.

[@dylanfiore3718]

And know I realized why my eyes had been looking at an all jumbled.

[@daveforfav7650]

Thatsnicekeepitup

[@daveforfav7650]

Mohammedhedidntputaspacebarbeforethankyouitsaperiodthankyouforyourtime

[@milkywegian]

daveimgay

[@daveforfav7650]

Whyutellingmethat

[@AlexRaxach]

as usual, it's going to take a week to assimilate and fully understand the video :)

[@oscaralonso4699]

same.

[@XiaoMingXing]

isn't ur face profile from an anime? I think its name is Greed?

[@AlexRaxach]

King PufflePuff spirited away

[@XiaoMingXing]

Yeah, that's what I thought. xD

[@nathanj2439]

King PufflePuff its original name was No Face

[@jakubbuzalka2226]

This video feels like a huge injection of liquid physics into my brain. Thank you!

[@ganaraminukshuk0]

"We have a box, a ring, and a marble." (Mario cube, LotR ring, and dragonball appear on ramp.) This is gonna be good.

[@MartijnvanWensveen]

Moments of silence.. This video has none!

[@RainbowManification]

Nope, just inertia

[@shaheer_ghazi]

I just spent 5 minutes of my life opening and closing my door at difference angles and lever arms

[@DanGash]

I'm giving Crash Course a shout out on my graduation... in 2 weeks!!

[@zacharykrawczyk3942]

There's an error at 6:27 the second part of the equation has KErot labeled as "kinetic energy of translational motion" instead of "kinetic energy of rotational motion"

[@ogliara6473]

Thank you for helping me through my physics assignment. Great video!

[@rafaelwilliam3805]

7:17 i almost had a heart attack, i sat in the libary and thought it was a school shooting lol

[@giovanniadelfio5378]

Thanks, this was the exact problem my professor asked me about in the oral exam!

[@tommclean9208]

Im doing Marine Engineering where there is a dynamics module which I did just not understand at all, these videos are so useful. Thanks.

[@jomacr3]

I could not get through Corona virus distance learning without this. Thank you!

[@abdulrakeebalsarori8171]

I am sorry, but how would the box get down before the ball or the ring? We already assumed that the surface is frictionless and so there would be no friction force that would cause the ring, or the ball, to rotate. Therefore, there would be no loss( or transformation) of potential energy to rotational energy of either the box or the ball.

[@Kronimiciad]

If the ramp only allows static friction and not kinetic friction, then the box shouldn't go anywhere if it doesn't rotate. In order for the box to slide down the ramp it needs kinetic friction. Static friction would mean that the box is stationary.

[@imjustsayin34]

First time using crash course for physics and was expecting hank but I was pleasantly surprised the speed she talks is nice

[@En_theo]

@5:05 Should it not be "kinetical energy of rotational..." in the bottom equation ?

[@Lee_yourboylee]

Love it, a very helpful accompaniment to my textbooks. Thank you Crash Course.

[@williamcoley1]

If the ramp has no kinetic friction, then there is nothing to start the rolling motion of the ball and ring, ergo they would all reach the bottom of the ramp at the same time.

[@SauceyNoodle]

Learning physics from Symmetra

[@madamii]

I'm 13 in eight grade and I'm watching this because we have to learn about it soon. Im trying to be above everyone else!!!!

[@FirstRisingSouI]

Watching at 1.5 speed because I'm a physics grad student, but I feel compelled to watch everything Crash Course puts out.

[@stephaniejoelstro1762]

This series is so good.

[@safa9408]

My head has blown up, I wanna cry, and my acne is back after watching one video

[@missychuu]

She is gorgeous btw.... And I love her hair 😍

[@willzer808]

God yes

[@pairot01]

She is, not that it matter really.

[@feldinho]

stop objectifying her! she's here to teach physics!

[@willzer808]

Felds Liscia whatever, everything is relevant

[@charliehutch3533]

go to India..they literally all look like her.:P:

[@alluringorchid5725]

Thanks for helping me out with class 11 physics . Exam tomorrow

[@madLphnt]

The one youtube vid i look forward to all week!!! awesome

[@nathanbanks2354]

I love the Elvish characters inscribed on the ring! Now I know why it's difficult to roll a ring into a fiery volcano--it's better to get someone to bite it off your hand and fall instead.

[@sunrise682]

I swear to god no matter what im learning theres a crash course for it

[@KrutarthBhatt1]

Mr.Green , this kind of videos make crash course my favorite channel.

[@ezekiel0606]

that pyshics theme song intro gave me chills just like the philosophy one

[@bidishamukherjee3936]

best best best best best!!!!! i could not get the chapter while reading from book but crashcourse made me understand it soooooooooooooooooo wel!!!!! thanks a lot lot

[@minghuiliu451]

If kinetic friction is not allowed, why will the marble and the ring roll instead of slide down?

[@GCMCRN]

At time 5:07 there's an error in the description of the formula for kinetic energy of rotational motion, it's written translational, like the upper one.

[@bennemann]

At 5:05 there is a mistake in the video: it shows "translational motion" for the second line too, which shold be "rotational motion".

[@mirrorizen]

That’s crazy, I thought the box would be last and ring would be first since it looks like a wheels. Thanks Dr Shini Somara!

[@nekomatafuyu]

If the ramp is perfectly slippery, I'm wondering if the marble and ring would start rotating in the first place. As I'm picturing it in my mind, they start rotating due to the frictional force where they contact the ramp, but that force isn't there in this example (otherwise the block wouldn't slide (or at least would lose energy due to the friction)).

[@Rhaegar19]

Rolling objects use static friction because the point where they touch the ramp isn't actually moving (see last video).

[@McGeias]

+Rhaegar19 no no no. The last video was an example of rolling without slipping. A frictionless ramp has infinite slip. There is no counterforce in this hypothetical example turning linear momentum into rotational momentum. Gravity does not impart spin magically. It's a linear force. It the surface friction that converts linear motion into rotational motion. That friction has been eliminated in this example. This is all just wrong.

[@Rhaegar19]

+McGeias Everything you're saying is right, except the ramp isn't frictionless. It has static friction. Rolling objects use static friction to convert linear motion to rotation. If you don't believe me or Dr. Somara, google it for yourself.

[@Alesster101]

This video cured my insomnia. Good morning guys.

[@damienscullytoo]

these physics videos are really helpful especially before my test

[@voidspork7150]

Note that the ramp is frictionless. If the ramp had friction, the marble and ring would likely get down faster (specifically, the marble) because rolling friction is less powerful than static/sliding friction. That said, the example is meant to illustrate how torque and conservation of energy work, so mentioning friction would be counterproductive to the video.

[@fredasanders3948]

Hi this is Arwen I love Crash Course!!!!!

[@tifanypan6948]

At 5:06, do you mean kinetic energy of rotational motion over the KE rotational block instead of translational motion?

[@asadgandapur9950]

kindly also make a video on projectile motion!

[@victorianightshade4237]

Just refreshed and boom

[@fabd1923]

this video was very helpful, thanks guys

[@davidlei3097]

At 5:07, there is an error. The bottom part is suppose to say "rotational motion", not "translational motion".

[@nandodando9695]

That was clear and went right in. Thanks

[@terrysullivan5276]

thanks...im finally read for my test tomorow

[@shairiaaz8298]

i am really surprised how you taught that........i didn't ever felt it that easy and intresting......i must say good job

[@skkhan-jg4jk]

U explaination is awesome my mind blows up

[@ImChrisNotChrist]

As a car guy, I very much appreciated that video. Solid host too

[@edwardmcdonagh7309]

you explained this way better than my university lecturer, good job!

[@软航]

The short video really did good job to make a brief interview of phsical knowledge.

[@theblackreaper4395]

Loved the video but in the case of the ramp, I'm pretty sure that friction between the box and ramp is kinetic, there is relative motion B/w the two surfaces..

[@Benmnoma]

This woman saved my life

[@adriel4040]

Okay, some of this stuff is a bit confusing but so much more confusing is the way teachers explain it in class. I swear i learned more in the last 10 mins than the last three weeks.

[@vicraaiman1205]

What's about the friction they have when goes down? The box has more surface than the marble and ring, it means the box have more friction than the other. So it will be slowed down

[@adamlevy8971]

These videos are incredible. They are really helping me with my college course. Thank you! :)

[@fahamedi]

They could've mentioned the physics of backflips, because when you jump and tuck your kness you decrease the moment of inertia of your body and you rotate faster due to conservation of angular momentum

[@ameenferry4988]

Maaaaaan she never stops tourqing

[@seaniwu]

Linear momentum is the product of moment of inertia and the angular velocity if and only if the axis of rotation of that body is a principle axis

[@alexsarullo3753]

The ramp example is flawed. For rotational energy to be taken into account, friction must exist to make the ring/marble spin. If the object make contact with a 0 friction surface, they cannot engage in spinning, they would just slide down the ramp.

[@lightspeed2014]

Alex Sarullo agreed

[@lightspeed2014]

It’s like kinetic friction works for the ring and the marble but not the box

[@marinairitsyan]

Very detailed explanation. Thank you!!

[@matchavoids]

I'm barely passing AP physics yet I pass all my Duel Credit classes with 100%+ i just- feel dumb. This video is good for reviewing before a test on Torque and Inertia.

[@ardhieavenido2178]

Hey ThoughtCafe! content inaccuracy at 5:09. The other one should be "kinetic energy of ROTATIONAL motion".

[@krossbow_]

I graduated 5 years ago, im a veterinarian, why do i enjoy learning about torque

[@nobodyofnaught2]

Why is it that the Marble and Ring even start rolling rather than simply sliding down the ramp with no rotation just like the box? I think there's something about the interaction of the hypothetical scenario where Static Friction exits but Kinetic Friction does not but I can't wrap my head around it.

[@pavitramurugesan9092]

I love all ur crash course video ! This physics is awesome.But I have a request all your physics crash course video are on class 11 topics I would be happy to have some new videos on class 12 topics

[@YEKOBness]

pandora started a dubstep song at the beginning of this video. I was so hyped on when this race started.

[@HonestUsedCarReviews]

𝐓𝐨𝐫𝐪𝐮𝐞 𝐰𝐢𝐧𝐬 𝐫𝐚𝐜𝐞𝐬

[@josephpark2093]

This looks threatening.

[@InventTwig]

Correction ! : even if there is no external torque on a 'system of particles'/'particles' angular momentum is not always conserved(only for some special points. angular momentum wrt to allpoints is conserved when the rotating body does not have any angular acceleration AND the axis of rotation passes through COM. angular momentum of a point can change depending on from where you observe it (both in magnitude and direction).

[@CharliesGayBandYo]

Doesn't the potential energy not include sin theta as it's going down a ramp at an angle and not straight vertically down?

[@alexkid1]

So, what is the difference between torque, angular momentum and moment (as you often hear in engineering). All of them seems to have the same definition i.e. force x distance.

[@DMikov]

I love your videos! please keep it up! May I kindly suggest to take a moment to breath... hehehe the paste is so fast! :) lil breaks :))

[@yogesh4596]

6:36 I don't understand why she cancels mass with the movement of inertia of marble and ring?

[@cpsneto1]

Great video!

[@gavinerecre8210]

your videos are awesome now I can understand

[@TheLittleGuy1]

Pretty and smart I think I am going to be watching more of these videos

[@audreyandremington5265]

I'll never watch LOTR the same way again.

[@AmirMohammad-fd9nr]

that helps me a lot .GREAT THANKS for your useful videos.

[@infinitasalo472]

This helps a lot, just what I need for exam review!

[@9000Arko]

dont you love when Pharah is teaching you about torque

[@gowgowgowgow7215]

That's so amazing a course!