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Uniform Circular Motion: Crash Course Physics #7

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Did you know that centrifugal force isn't really a thing? I mean, it's a thing, it's just not real. In fact, physicists call it a "fictitious force." Mind blown yet? To explore this idea further, this week Shini sits down with us to discuss centripetal force, centrifugal force, and a few other bits of physics to help us understand uniform circular motion.
***
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Опубликовано:

28 авг 2024

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Комментарии : 870

@crashcourse Год назад

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

@dezent 8 лет назад

She kept me totally focused for nine minutes and twenty six seconds and i learned lots of new stuffs i did not know before!. Really shows that you guys are getting more and more professional.

@LeRouxBel 8 лет назад

Great, now I lost my key.

@rat7710 8 лет назад

I lost my ignorance :)

@carmelogonzales5053 8 лет назад

I use a Knife My key is safe

@carmelogonzales5053 8 лет назад

That flying Hit my brother and now his gone. Lol i have no Brother.

@davidcobb2682 5 лет назад

@@carmelogonzales5053 not any more

@mufaddalezzi2293 8 лет назад

just an idea, you should have an app where you can compete in a quiz with a stranger based on the material from your videos. It would help learn better.

@amnawajahat6418 6 лет назад

quizup

@jessmoser7322 5 лет назад

or quizizz

@sharathkumar8422 5 лет назад

This is a brilliant idea to increase revenue and viewer count... CRASH COURSE! LOOK AT THIS!!!

@kynslayer 5 лет назад

Mufaddal Ezzi quizcourse

@calebmeeks442 5 лет назад

so a review just do quizlet

@AxisSpark 6 лет назад

2:45 The fact that phys is a required course for Computer science majors with a concentration in game development and crash course incorporates video game references in these videos makes learning all the more enjoyable!

@WriteUnread 8 лет назад

Please god someone fix that Rubik's cube I'm dyin here

@thelonelydirector 8 лет назад

+Holly Panetta I have bad news for you ;)

@WriteUnread 8 лет назад

+thelonelydirector :(

@thelonelydirector 8 лет назад

Blame Hank, he's the one who started playing with the cube in a meeting and now it's forever that way. FOREVER!

@WriteUnread 8 лет назад

+thelonelydirector :(( my poor order-loving brain can't take this

@MARK_2130 5 лет назад

When I play rubic's cube sometimes I cheat it

@drink15 8 лет назад

Hank is looking good!

@rileypurcell2159 8 лет назад

+leein jeon Hank usually hosts the CCs that are filmed in Montana.

@djbslectures 8 лет назад

Who the eff is Hank?

@drink15 8 лет назад

DJBsLectures I hope this is the first video you watched on this channel.

@djbslectures 8 лет назад

+drink15 store.dftba.com/collections/vlogbrothers/products/who-the-eff-is-hank-poster

@drink15 8 лет назад

DJBsLectures OOOOOoooooo. Well played sir!

@krismoe31 7 лет назад

I am at the bottom of motivation atm and I have a physics/chemistry exam in 1.5 weeks. So nice to have easy "lectures" on youtube. Thank you guys!

@vectoredthrust5214 8 лет назад

"We're just here to make sure the ride is safe, we're not responsible to clean up all the vomit after the ride is over" Bahahaha, I'm sure the engineers agree xD

@MartinPereira-qn2mt 8 лет назад

+Vectored Thrust That's the rocket builders motto

@zhto514 5 лет назад

Last video 5 years ago bruh 😃😅

@fredschwartz3654 8 лет назад

Great video. I'm close to 70 and live in the US, but when I was her age, we pronounced about 73% percent of all those big words differently :-) , Love it. I could listen to this video a dozen times. (and might have to . . . and take notes)

@seantimchew 7 лет назад

Bless you guys, this has practically saved my GPA. So much easier to understand than what's taught in school

@simplySwag7567 4 года назад

I remember when i was back in 8th grade i couldn't understand a thing she said. I jus thought she was one bad teacher with crash course. now in tenth grade, this is the most clear explanation i have found yet. Thanks!!

@neilsanders8163 4 года назад

No idea is original, everything stems from something. To brake it down the more you understand the basics, the easier all the new stuff gets. You can't have the newest phone with out starting with the Nokia brick A.K.A THE OG (the struggle was real).

@killersquirrel9 8 лет назад

I just failed my ap test this week, really could have used this earlier rip

@crashcourse 8 лет назад

+Yale Benson I mean... I usually know when I've failed an exam.

@killersquirrel9 8 лет назад

+CrashCourse ya... Not answering half of it was my first clue

@leaderoftaehyungnation9766 8 лет назад

Can't you re sit the test?! 😪

@frankschneider6156 8 лет назад

+Dan Gilbert Learning sometimes helps .. just a thought

@ZVPieGuy 8 лет назад

This video wouldn't have helped you on the AP at all.

@meredithmcdonough5885 4 года назад

currently watching this 3 hours before my AP test. god bless your soul

@TGC40401 8 лет назад

You spin me right round... Thank you for your time.

@Sleepy_Fox 5 лет назад

😂 nice one 😂

@LucasCamargosRamos Год назад

1:21 I was pretty concentrated on the video and thought I was just about to pass out. Well played. 10/10.

@nachannachle2706 7 лет назад

It's interesting to notice that as we go further into these videos, the explanations make more and more (intuitive) sense. That's is great course outline work, folks!

@dm_nimbus 8 лет назад

Why is Crash Course always awesome? Is there some quantifiable element?

@mjpanicali 8 лет назад

+James Craver CC Physics is 2.7 less quantum units of awesomeness than CC Government and Politics (no eagle punching is negative factor).

@Byamarro2 8 лет назад

+James Craver Now I know from where Kurzgesagt seeks for materials, haha

@bananaman7458 8 лет назад

Kurzgesagt is awesome!

@dm_nimbus 8 лет назад

+Bananaman Agreed (I'm a patron with a bird profile pic; not actually affiliated with them)

@imaaduddinshaikh221 4 года назад

It smells like months of hard work Famm

@TheWizardYoshi 8 лет назад

Circular motion was my favorite section of physics last year, awesome video!

@SotraEngine4 8 лет назад

This will save me in the physics exam in 12 days

@rainick 8 лет назад

+SotraEngine4 Sounds like you need a better physics class.

@dragonjade8853 5 лет назад

SotraEngine4 same

@oogabooga8447 4 года назад

this will save me on the physics exam in 16 hours. and i have the flu.

@betatree 8 лет назад

Damn these physics crash courses are super clear! I hope it'll help a lot of people struggling with their mechanics class :)

@zachariahfurlotte 8 лет назад

Hey guys, awesome videos ! You guys have been teaching me material non stop all the way from grade 10 Advanced Biology to first year university Psychology and I just wanted to thank you for all your dedication and hard work ! I just transferred from a BSc to BEng and am studying to become a Material Engineer so I'm taking several physics courses in the spring/summer and am exactly where you guys are right now(Video Wise) ! P.S. I think I've gotten almost all my friends to watch your vidoes if they need help ! :D Thanks for all the dedication guys !

@Kaalyn_HOW 8 лет назад

The key turning 'experiment' is basically how discus throwers don't knock out anyone standing beside/behind them.

@christinarobyn9820 6 лет назад

I'm in university physics and these videos are incredibly helpful! Thank you

@brennahasselmann8075 7 лет назад

I love that you explained how the variables in each equation made sense in reality, that's the one thing that was keeping me from understanding

@OmicronVega 8 лет назад

@Dr. Shini Somara You're just the whole package. I could listen to you could talk physics for hours. :)

@Autotunethyeveryday 2 года назад

CRASH COURSE IS IMPORTANT ALWAYS

@perpetualpolymath5961 8 лет назад

1.Lets prove a = v^2/r if v = (2 x pi x r)/T 2.v= (2 x pi x r)/T 3.using chain rule 4.dv/dr x dr/dt = dv/dt = a 5.therefore dv/dr x v = a 6.dv /dr = (2 x pi) / T 7.dv/dr x v = ((2 x pi)/T) x ((2x pi x r)/T) 8.dv/dr x v = (4 x pi^2 x r)/T^2 9.dv/dr x v = (((2 x pi x r) / T)^2 )/r 10.we know that v = (2 x pi x r) / T 11.therefore 12dv /dr x v = v^2 / r 13.hence 14.a = v^2/r 15. Q.E.D if anyone is confused at 9 a quick expansion shows that line 9 equals line 8.

@saeedbaig4249 7 лет назад

"4.dv/dr x dr/dt = dv/dt = a 5.therefore dv/dr x v = a" I can't see the leap of logic u made from 4 to 5. When u say "dv/dr x v", r u saying that v is dr/dt? I that it v was dc/dt (where c is circumference).

@perpetualpolymath5961 7 лет назад

Sideeq Mohammad Simple chain rule is at work here. dv/dr x dr/dt =dv/dt , think of it like the dr's cancelling but the actual proof for chain rule is quiet long. we know dr/dt is basically the rate of change in distance and we all know that is velocity.dr can be exchanged for dx here thus dr/dt = v hence dv/dr x v = dv/dt = a.

@saeedbaig4249 7 лет назад

Mo Killem Ok Im familiar with chain rule now but, as an aside, shouldn't dr/dt=0? After all, dr/dt is the rate of change of the RADIUS with respect to time. But the length of the radius NEVER changes in uniform circular motion.

@perpetualpolymath5961 7 лет назад

Sideeq Mohammad It doesnt change in magnitude however it changes in direction and hence it does have a rate of change.After all displacement is a vector.

@saeedbaig4249 7 лет назад

Mo Killem O ok sanks 4 clearing dat up

@jassenbuerano 8 лет назад

man, you guys should have done this last year, it's literally perfect for AP physics review.

@DistortedMatt 8 лет назад

Too bad this was posted after the AP Physics Mechanics test! Still a great video and I am happy that Crash Course isn't afraid of covering a math heavy subject like physics.

@realmenchangediapers 8 лет назад

Why did I live to the age of 34 before I found out that centrifugal force doesn't exist??

@Eveseptir 8 лет назад

+realmenchangediapers It exists relatively speaking.

@HaydenHatTrick 8 лет назад

Yeah, I get annoyed when I try and explain physics to people and they refuse to use fictitious forces. Because "their not real" Actually, you can think of fictitious forces as forces experienced due to being confined to a surface during motion. Because that is an entire field of math in its own, simply using forces produced relative to the object on the confining surface is stupidly efficient and true to what you actually experience.

@SidPhoenix2211 8 лет назад

i found that out in a Horrible Science book, when I was in sixth grade

@tutocfproductions7065 7 лет назад

So if it doesn't exist, why do we build things based on it and they work perfectly?

@h20falcon59 7 лет назад

we don't centrifugal is just a name we give the machines we base them on centripetal forces, if for instance centrifugal force did exist, we wouldn't be able keep satellites in orbit they would go further and further away from the earth, and those centrifugal machines, have an arm attached to a giant pole in the center for a reason. :)

@ExplodingPinapple 8 лет назад

2:47 Oh hi there, Link! How are you?

@reebam8914 6 лет назад

You videos have helped me so much in Physics. I couldn't find any reliable, informative and yet interesting video like these ones. I can't thank you enough. I'm more than thankful to you. 😊😊😇😇

@sondirobianto1548 8 лет назад

please make crash course programming

@noirerequiemii101 8 лет назад

That'd be a dream. But VERY LONG

@fossilfighters101 7 лет назад

@undergroundskeptic2916 7 лет назад

YES

@ShamsaShakir 7 лет назад

@chlojo 7 лет назад

We now have Crash Course Computer Science. That's pretty good

@buenchiko007 8 лет назад

this came at the right time to reinforce what i already knew about circular motion in a cool, graphical way for my exam tomorrow. Thanks for this upload!

@thenellecornejo3724 4 года назад

time to re-watch this 5 more times

@TheSYLOH 8 лет назад

"I'm getting dizzy just think about it" She said as she cut to a graphic of SPINNING GEARS.

@TakaG 8 лет назад

+CrashCourse Small tip. The editing is too fast. You are not giving the viewers any time to take in what they just heard before going into the next sentence or point. Leave a small breather. Just a second may be enough. Don't rush things, especially with scientific subjects like this one.

@j26walker 7 лет назад

It's called crash course for a reason.

@TakaG 7 лет назад

j26walker The things I have listed have little to do with actual crash courses and more with video editing. Many videos, especially on youtube, are edited poorly and way to quickly with awkward pace shifts. Giving small breathers helps the viewers digest what they just saw and heard. And keeping a proper pace and changing it at the right moments also helps with conveying information and mood. This applies not only to educational videos, but movies and everything else as well. An appropriate rhythm is important. That's the difference between the Transformers bad edits and the Avengers great ones. ;) That said, Crash Course usually does a very decent editing job. This video was way too quick paced though.

@amsed7942 7 лет назад

Takako Jin I mean you can pause the video

@bhaktisagar4089 6 лет назад

Jst watch it more den 1 time

@dragonjade8853 5 лет назад

If on phone, try slowing any video down to .75. It helps

@ahorrell 8 лет назад

She has the best hair of any Crash Course host, WAAAAAAAAY better than Craig from Crash Course politics.

@culwin 8 лет назад

+Aaron Horrell What about Phil Plait

@tennicktenstyl 8 лет назад

Didn't understand anything, sugar still gathers in the center of my tea cup.

@HaydenHatTrick 8 лет назад

That would be due to centripetal motion (a force going towards the center of rotation). The only difference is that the system is more complex.

@samsonclement7604 6 лет назад

When you stir the cup, water is forced outward because of centrifugal force, the same sensation you get when riding a carousel. This makes the pressure higher towards the edge of the cup. Close to the bottom of the cup friction between the fluid and the cup forces the swirling motion of the water to slow down and this in turn makes it possible for the pressure difference to establish a current towards the center of the cup that is stronger than the centrifugal force.

@yeet6764 5 лет назад

@@samsonclement7604 I thought she said centrifugal force doesn't exist

@FrumpybutSuperSmart 8 лет назад

Everything in this one made sense! I think I'm learning things.

@sexysexminecraft 7 лет назад

"They knew a big part of space flight involved acceleration" -biggest understatement in history.

@AliKhan-ox3mr 4 года назад

So What is the REAL big part of space flight?

@AliKhan-ox3mr 4 года назад

So What is the REAL big part of space flight?

@user-bl8cm9pw8i 9 месяцев назад

Hi this video was so amazing keep up the good work love you all so much

@harmonyofnature4747 8 лет назад

Homegirl in the video is really beautiful and very well spoken

@BeHappyTo 8 лет назад

+Harmony of Nature almost distracting

@Nemoticon 8 лет назад

+Harmony of Nature Dr. Shini Somara... I believe she's Indian.

@kolbeowen3052 4 года назад

1:22 the editing though

@mantasreika 8 лет назад

She is so good!

@Ashley__Elyse 5 лет назад

This video explained Uniform Circular Motion in nearly ten minutes better than my teacher in almost a week. Thank You!

@Malfunct1onM1ke 8 лет назад

Hooray for the guy who ends up cleaning up all the vomit \ o /

@thegaspatthegateway 6 лет назад

thank you thank you for the visual representation! (color coding the variables / connecting the variables with a line was also a nice touch :) )

@alanbannister1874 4 года назад

I love how they have the ‘Feynman lectures on Physics’ on the shelves. Great books.

@alexjordan8838 8 лет назад

I love physics and all, but her voice is beautiful

@MusiCaninesTheMusicalDogs 8 лет назад

And so are her eyes.

@lema1425 5 лет назад

after having no idea what’s been going on in physics for a week and having a test on this tomorrow, it just made complete sense.

@alexismonster64 8 лет назад

I was whating for this one for a while

@crashcourse 8 лет назад

+Alexis Trodglen Hope you enjoy it!

@maximusdizon7267 8 лет назад

you were what??? whating...ok well then ...😑

@Brandyalla 8 лет назад

+Master Max JEDI Maybe it's shorthand for "waiting for whales"

@maximusdizon7267 8 лет назад

OK I didn't know that lol

@rohitreddy6794 6 лет назад

Best channel for physics

@Ray-ye8gz 7 лет назад

Honestly, those physics videos are really helping me out! In fact, A lot :-)But you need to repeat the video and focus a lot on what Shini is saying.

@riyam02 7 лет назад

Brilliant course with this one, and a very intelligent instructor. It's well broken down, and conceptually it just makes sense in under 10 minutes.

@olizelda 7 лет назад

GREAT! I did you little key demonstration in my backyard, and now I've LOST my HOUSE KEY in the grass!!

@IceMetalPunk 8 лет назад

Uniform circular motion is fun. Rotational dynamics, though...I could never get my head around that. I understood relativity perfectly fine, but as soon as we started discussing torque, I was so lost. It didn't help that I had a professor whose answer to "where did that equation come from" was just to write more equations on the board with little to no added explanation...

@joekenyon1599 8 лет назад

that's been my teacher pretty much all year lol.

@ashutoshkumawat3690 6 лет назад

Your eye contact is appreciable along with your stuff...it kept me focussed.

@lukasdanarm 6 лет назад

This so helped me. I have a circular motion test in physics tomorrow and this really saved me.

@josephmontoya942 8 лет назад

glad these videos are clearer now

@eichi7618 8 лет назад

Ahh, wish these physics topics were already finished lol, woudve helped so so much in my physics exam just like how much it has helped me in bio and chem! Found the biology 8402 igcse paper 1 so easy mostly because of CrashCourse!

@luismartinez-ue4fv 8 лет назад

if the teachers of the world give the classes like this video, i would never miss one. Love CrashCourse

@rmatkins16 8 лет назад

I'm so glad they've sorted out the heights of the lights behind her, it's all my brain could focus on before!

@12Rman21 8 лет назад

did you just squeeze in dimension analysis at the end there? That might deserve a little more attention since it's a super usefull tool for checking any calculation you are doing. And it gets only more important the more complicated your equations get.

@Sentinalh 8 лет назад

That was a lot of math, but I think I got it. Also Shini is beautiful.

@Jewboyjacob 8 лет назад

WTF!!! A thought y'all had this whole physics series!!! My Physics Exams Tomorrow!!

@mosajid7861 8 лет назад

Same but my exams in an hour

@TheRealADHDavid 8 лет назад

Dr. Shuster is a teacher at my High-school :D

@rileypurcell2159 8 лет назад

@MIQofDMC 8 лет назад

+Riley Purcell 9:39 consultant - Dr. David Schuster

@rileypurcell2159 8 лет назад

+MIQofDMC Oooohhhh. Lucky you!

@daroastftw7579 7 лет назад

Thank you so much! In our intro to uniform circular motion, we rushed through some derivations, and the concept wasn't really explained. Thank you for putting words to variables and numbers!

@artofthescreenshot2574 5 лет назад

Physics aside the intro is LIT. Love this channel.

@wingedlionn Год назад

screaming if i had seen this video a week ago i wouldnt have failed my physics a level lmao

@davidsweeney111 8 лет назад

In classical mechanics, a reactive centrifugal force forms part of an action-reaction pair with a centripetal force.

@MauricioMartinez0707 6 лет назад

You see that sounds right but everyone keeps saying it doesn't exist. But yes in my head it's similar to the normal force

@MrSun-gk5kl 6 лет назад

I'm studying for my senior year physics exam so I'm no expert but I'm 99.99% sure this vid is correct on the centrifugal force being a fictitious force

@mjsaedy6637 6 лет назад

Not true, the action/reaction pair do *not* affect the same object: the centripetal force applied to the object is the tension force from the string, the object exerts a reaction force *on the string* , this reaction force has no interest to us since we are studying the rotating object not the string. To realize why the Centrifugal force is not real, just examine what happens when we cut the string: there is no more Centripetal force so the object moves along a straight line that is a tangent to the circle (in the direction of the Velocity at the moment the string was cut). If there where an actual Centrifugal force, the object should have moved in a straight radial line *perpendicular to the tangent* , which is not what happens in real life.

@onglinwei2418 5 лет назад

Centripetal force is actually a resultant force so there's no centrifugal

@franksmith9027 5 лет назад

@@mjsaedy6637 You say:"Not true, the action/reaction pair do not affect the same object:" Of course they don't, if they did they would cancel each other out. When you swing a ball on a string your hand exert a centripetal force on the ball which reacts by exerting a centrifugal force on your hand and it is obvious these forces pass through the string. You thus have an action/reaction force pair that obeys Newton's Third Law.

@leopoldopascuaii3007 7 лет назад

Thank you Crash Course Physics.

@benth162 8 лет назад

I am very please to see a woman explaining things that used to be mainly in the domain of men. Very well done young lady, my hat is off to you. BRAVO !

@TheTrueTeX1 8 лет назад

Love the fact, that you took Link for the depiction! :D

@LagMar100 6 лет назад

Overall great video and examples! thank you CC team! :)

@rakshaaiyappan8193 7 лет назад

Hey there, thank you guys for these awesome videos!

@caitlynemily892 6 лет назад

honestly these videos are the only thing saving my ap physics grade

@arjunabraham9035 8 лет назад

These videos would have been so useful on Monday.

@Whatyamightcallit 8 лет назад

WHY DOESNT THIS FANTASTIC WOMAN HAVE A WIKIPEDIA PAGE? SHE DESERVES ONE, sorry for the caps, but i was so surprised about this

@livmyhre5189 Год назад

the link reference was so cool:).

@shoeeey5319 7 лет назад

I love these videos, they're so useful for my exams! thank you!

@IceCreamMilkshake777 8 лет назад

oh yeah and please do momentum and angular velocity and angular momentum pleaseeeeeeee

@echodots 8 лет назад

I swear I had to replay this one 4 times just to figure out what was the difference between the analogy of the car versus the key lol. I love watching things that make me go grab a pen lol.

@AyeshaKhan-gp9on 7 лет назад

Hey, those rides are fun, not nauseating!! :P But yeah, they're intense. :)

@ashleya1601 7 лет назад

We're just about to start this in class, HELPED SOOO MUCH!!!

@sirherbz 7 лет назад

my most productive 10 minutes, thank you ~

@PragmaticCulture 8 лет назад

Crash Course for the win helping me study for physics.

@s4236521 8 лет назад

Shini could explain anything and I would listen wholeheartedly. Can we crowd fund her to record a phone alarm so I can stop hitting snooze? That, or you know... just persuade her to dub over my Discrete Mathematics professor.

@marvcyclone4167 4 года назад

got a test next period, wish me luck

@annamckelvey6380 5 лет назад

Bless that Link cameo

@sidrabarry1921 7 лет назад

These are so great to watch after going through text! Great way to reinforce the information, thank you!

@davidconnolly1130 8 лет назад

My physics mark: brought to you in part by Crash Course Physics

@jennihaataja932 8 лет назад

"So engineers tested potential astronauts by putting them in a human centipede."

@AhmadAli-sh1xv 8 лет назад

She really has a clear way of explanation compared to a lecture but i feel that is from the fact that she has the time and the ability to use accurate graphics, though I also think that is why she could go at such a quick pace, though that also makes me want to see more calculus in the show, you know introduce the basic parts then get more technical and mathematical. Though maybe I am asking for too much. although I am using although and though to much.