Work, Energy, and Power: Crash Course Physics #9

[@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

[@garethdean6382]

Let this be a lesson to all of us, if you want power you're going to have to put in a lot of work over time.

[@Bunnyhop2002]

that actually helped me memorize the formula..thanks!

[@lydiascott5808]

Same. My teacher doesn't know how to teach so thank you so much lol.

[@raggledaggle721]

which equals exploitation.

[@alexcsouza]

Depends on the system...

[@srishtipandey1025]

what

[@ahzhd423]

This was uploaded... ...the day after my physics exam...

[@eleanorthekoala7256]

join the club

[@thekingmeruem]

the same here lol

[@user-yx7dp2pl8t]

they probly didn't want the blame

[@KennedyBoston]

MY PHYSICS EXAM IS TOMORROW PRAISE THE ALL MIGHTY GODS OF CRASH COURSE!

[@heroman1596]

same herw

[@realmenchangediapers]

Lots of stuff going over my head and that I will forget. But I love listening to a lesson and not being forced to understand it. I can just marvel at the wonders of science and appreciate all those scientists with brain capacity well over my own. Thanks for making the world better with electricity, internet, smartphones and antibiotics.

[@nygeek6471]

Uhm...

[@Flameandfireclan]

What?

[@geico105]

They don’t have greater brain capacity than you, they’re just more patient and don’t give up when they’re frustrated.

[@samahf1669]

Studley De Muffin agree but he needs to study.

[@EugeneKhutoryansky]

Physicists have one set of definitions for these words, and the rest of the world has different definitions.

[@ASTCify]

Same deal with other scientists and the words "theory" and "prove".

[@georgebogurd]

Hi! Completely unrelated but I absolutely love your channel, can't wait for new videos.

[@Yaz.G0]

For me science definitions are always true , i always use hypothesis instead of theory in my life once i knew what scientific theory mean, and it makes sense.

[@UnforsakenXII]

Mappings and functions. Gross, haha.

[@chuvzzz]

Hey awesome videos guy, nice awesome videos

[@Jblade343]

I learned more in 10 minutes than i did in 3 weeks of physics. This would’ve been great to have before the unit. The explanation even uses past equations so i can remember them. Thank you

[@lsowner10]

I've learned more relevant things watching KZbin, than anything taught in school.

[@kennyemmanuelnaidoo4427]

Same here.

[@jairousparker2311]

G. Warren, I agree. Watch and listen again and again until you get it. Got it!

[@junkevidence]

@@kennyemmanuelnaidoo4427 "I never let school get in the way of my education" Mark Twain

[@azkiam7922]

thats cuz u dont listen

[@MusicSounds]

Same here

[@javierfigueroa7405]

I love how you blend the colors of the squares when solving an equation! Great work ThoughCaffe

[@crashcourse]

I too loved that! -Nick J.

[@tiaanengelbrecht9378]

I'm not even sure why I watch Crash Course Physics...I don't understand half of it, but I feel smart though.

[@danilooliveira6580]

if you try to read and study a bit about everything she says in parts, maybe following the same order of the series, and then watch everything again, I'm sure it will became easier. she also always say what kind of mathematical witchcraft she is using, so its easier to just go look a bit about it to make the math easier to understand.

[@BeCurieUs]

A lot of this stuff takes repeated exposures from multiple sources. It is like anything you do, be it league of legends or math, it takes time and practice :D

[@VirtualCockpitChronicles]

I'm the same, I wish it was easier to retake my maths and science courses from school so I could actually understand these.. What grade are these videos aimed at? In the uk I only took GCSE's which we do at 16 and this is a lot more advanced than those, oh and it was nearly 20 years ago so I don't really remember much either!

[@frankschneider6156]

What she is doing is basic mechanics, so it's the stuff you do in 7th grade

[@frankschneider6156]

TSLNC04 No, not in the US but in Germany. but here e.g. calculus is also mandatory curriculum in the 11th and 12th grade

[@crushcollegechemistry]

Watt is power?

[@goodsir2551]

Watt is effect. WAs it a bad joke or a question?

[@crushcollegechemistry]

A bad joke

[@TheMitchy27]

Ryan Cerny How about you find out by doing your WORK?

[@crushcollegechemistry]

Ha!

[@benjaminanderson2718]

smh

[@mpeifj124]

I'm so annoyed by the state of that Rubik's cube

[@ladidakalana4233]

Ahh Yeahh

[@antisocialpill]

ocd fellow

[@jetkwan2935]

Muji Paracha that's entropy to you

[@nasa9439]

Muji Paracha that bugs me too. I hate when I see things left like that.

[@nimo3493]

OCD

[@celt2453]

I WAS LITERALLY STUDYING THIS RIGHT NOW. Thank you very much

[@crashcourse]

You're very welcome :) -Nick J.

[@samuelsilver8077]

To salt mines you go :)

[@ace_stealth251ace9]

OMG JINGLES I JUST WATCHED UR LASTEST VIDEO AND CAME TO THIS AND HERE U REPLY WTF WTF. OMG OMG . UR FAMOUS MAN. I SUBCRIBED TO U SINCE UR FIRST VIDEO. OMG JINGLES

[@ace_stealth251ace9]

+CrashCourse OMG AND CRASH CROUSE REPLIED TO JINGLES OMG OMG OMG OMG

[@ace_stealth251ace9]

+Stephen Mcfeeley DAM THATS NOT JINGLES

[@vedantkashyap9063]

Your videos are really helpful for reviewing some of the important concepts a day or two before an exam. Trust me if I would've watched this video without learning the chapter at a slower pace in school I would definitely feel lost😂😂. But thanks to your videos I've developed a lot more confidence than before. You are great teacher.THANK YOU

[@adamoreno2608]

This KZbin channel literally help me in every school assignment no matter what I choose. Whether it’s history or science I always find the answer

[@ayesha2014]

Okay. Thank you so much. Today was coincidentally the day when my teacher started this chapter in school and I come home to this video while surfing YT. God bless! Really love the simple and AMAZING explanations. Can't believe a boring physics lecture in school turned into a really fun YT Physics Crash Course. 11/10 would recommend.

[@me2143658709]

I just want to say I love everyone who worked on this. I'm in AP Physics right now and my teacher isn't the best at teaching (she would be better at the middle school level. She had=s the enthusiasm but lacked the ability to teach mathematical concepts). Your required to have either completed calculus already (like me) or be in the class right now (about half the class), so that means that means when it comes to some of the math, it's some kids first time seeing it. Yeah, not good. Anyway, what specifically made me leave this comment thanking you is that you actually called it an integral. Both my teacher and the text book have been dancing around the word because it hasn't been explicitly taught in class; and I have been ready to rip my hair out because I just wish they'd call it what it is. So thank you for keeping me sane.

[@samuelschonenberger]

I learned physics in German Now I have to translate everything in my head to follow

[@babblgamgummi6029]

Ich auch, aber ich finde dadurch, dass sie alle Fachbegriffe nochmal erklärt kann man sich ganz gut dran gewöhnen

[@hi9725]

Suh

[@cdespejo]

Just finished my University Physics 1 class and these are great refreshers. And in many ways, I retain the information better when i'm not in the midst of trying to pass an exam.

[@radicalbacon]

twinkle twinkle little star, power equals eye squared are.

[@shreyamary5948]

radicalbacon genius.

[@nodeUser]

P = I^2 × R you say?

[@nodeUser]

Let's see... P = VI Where V = IR Putting the value of V; P = I*I × R Hence proved.

[@poornimabhandare1168]

radicalbacon ewww

[@sunflowercara8691]

radicalbacon I'm going to remember that for my exam

[@petersoncastr]

My god... her accent... i'm in love...

[@hemantbhatia5859]

Peterson C. A

[@Unknown-ll3ew]

You teach better than my AP teacher

[@jazzling]

it's easier to learn something the second time + they're reading off a script

[@bmzaron713]

The explanation of convection and thinking how the position of the heat source can prohibit convection was the neatest part of this

[@8thfloormath369]

I love the way she puts it! I've never thought about it quite like that before. Awesome!

[@tedkinny4478]

Love how she stays in the subject, managed to understand most of my Uni physics classes!

[@julianszere]

work for people ---> job work for physicists ---> science work for me ---> rihannas song

[@asshole9191]

work for me -> a nightmare xD

[@webx135]

work for me -> science

[@Flameandfireclan]

Only work for me -> Eating

[@taeyang]

work work work work work

[@osamagaming727]

yah

[@ohthatsnot_]

0:07 is that rihanna on the wall hahahajahahahaha

[@shivanishastri4285]

Marah you’re awesome lol I didn’t notice

[@immortalpirate]

Marah Great f'ing eye!

[@florbz5821]

"You're basically a light bulb!" That was so funny! XD Don't know why...

[@chaohongyang]

My son loves your channel, and he is only 12. You have a great channel, lets go crash course!

[@clararose4057]

These are amazing! The presenter does a GREAT job. Please keep making them. It would be great to have a Calculus Crash Course as well.

[@arnavmanjul4464]

These vids got me a 97% on my physics test boi. Best vids keep doing them cause u deserve more subs.

[@aldomaresca9994]

this series is so well explained!! I cant wait to see how you tackle electricity and magnetism

[@Muhammad-f9l5i]

i had a huge test and i hadnt revised all of my work so this rlly helped me out ty btw i passed the test

[@muhxnnxd]

i guess this is my favourite series of crash course!

[@crashcourse]

NICE! :)

[@muhxnnxd]

CrashCourse damn! didnt expect a reply! but tell john that world history was super awesome too ;)

[@crashcourse]

Will do! -Nick J.

[@jona5820]

Why am I watching this? I have 20 pages of GR to write today. How can it be so entertaining to watch videos about stuff you already know?

[@Flameandfireclan]

I'm procrastinating my physics assigment to watch Crash Course Physics. Just kidding, who would do that. I'm just a construction worker. Love the series even though I feel like a 6 year old while watching this.

[@hamzahwarsi]

You do realise construction works need physics too

[@Flameandfireclan]

Mohammad Hamzah You don't need to be of higher intelligence to clean up rubble and put concrete on the ground.

[@hamzahwarsi]

Karadra Peterson I didn't mention higher intelligence, I mentioned physics like the basics.

[@Flameandfireclan]

Mohammad Hamzah Haha! Bruh, what I do. You barely even need basic arithmetic.

[@zacfox2743]

@@Flameandfireclan that surprises me

[@ryanweaver962]

Honesty, kindness and good work… work and energy and momentum. Work… fascinating how very important relativity and/or context matters. Lots of potential and kinetic energy.

[@TheBreezus]

PBS was very smart to endorse it! It is one of my fav topics on my fav educational channel. Also I invented insta travel based off of Breit-Wheeler process. Hopefully they will talk about it one day!

[@patrickwalsh4588]

I see this channel becoming the complete future of High School Education - I learned more in this video about Work than i did in a whole year back in GCSE's xD

[@PinkChucky15]

This was one of my favorite subjects in physics class.

[@srideviambati2558]

these are the best physics videos I have ever seen. she's wonderful and also the one who's doing these editing pics stuff

[@benjaminringrose536]

This video series is a great introduction to the fundamental principles of mechanical engineering, very well done!

[@samgraybillll]

this is the best physics video I've ever watched

[@jeromemagpantay3179]

Due to the pandemic, my physics teacher told us to watch this video in place of a lab.

[@echodots]

I may be the only one who noticed this but you were speaking slower and I'm glad for that. I really couldn't keep up on the previous episodes so thank you. #physicsnovice

[@nachannachle2706]

This was a really good input. Once again, it is fantastic to explore the equations and how they describe the same concept using different terms. It is 100 times more engaging than dull mathematical exercises. Looking forward to the course on power and electricity!

[@parmita52]

The way they do those animations with the equations is so beautiful and helpful.

[@ravindr22]

I love ur teaching as it never gets boring and the diagrams are clear and easy to grasp.. Thanks for making all this freee

[@senpaistudios5485]

tbh when the test is in one minute and your watching this, like no joke, help I didn't study

[@plankalkulcompiler9468]

Oh, did it go well?

[@ahmedadeel2246]

Best video made in the physics section- loving the rihanna reference

[@Breathingdeeper]

Work work work work work

[@MrSenset]

High five for Mel Brooks reference! 8-)

[@TubularOfficial]

thank you was looking for this comment

[@seandafny]

YOU ARENT WELCOME HERE

[@wadehosking4446]

Lol.. thank you...I was looking for this comment.

[@itswarhawk]

Rihanna

[@thirakhunsrismith]

🎯 Key Takeaways for quick navigation: 00:32 📚 *Work in physics is the result of applying force over a distance to a system, and it is crucial to understand forces before delving into the concept of work.* 01:54 📐 *When the force applied is not in the exact direction of motion, the work equation involves the force, distance, and the cosine of the angle between the force and the direction of motion.* 03:19 ⚖️ *Work is measured in Joules, the same unit used for energy. Work is a change in energy, and energy is defined as the ability to do work. Two main types of energy discussed are kinetic energy and potential energy.* 04:43 🌐 *Potential energy can be gravitational or spring potential energy. Gravitational potential energy is calculated as mgh (mass times gravity times height), while spring potential energy is half times the spring constant times the distance squared.* 06:39 🔄 *Some systems can lose energy through work (non-conservative), but conservative systems, like a simple pendulum, do not lose energy. Energy changes between kinetic and potential, and their sum remains constant.* 08:01 ⚡ *Average power is defined as work over time, measured in Watts (Joules per second). It quantifies how much energy is converted from one form to another over time, with an example of calculating average power in pulling a box.* Made with HARPA AI

[@daniellassander]

She is truely amazing, awesome video as always, loved every second!

[@asmaalrifai]

I've been watching A LOT of physics videos and couldn't understand until i found yours, thank you very much❤️❤️

[@KA-kl2ws]

Perfect video

[@crashcourse]

Wow! Thanks :)

[@nolansykinsley3734]

lol, 9 minute video, posted 3 minutes ago.... 2 minutes ago you comment "perfect video"....

[@radicaledwards3449]

+Nolansykinsley intriguing

[@power-max]

Watched it at 2x speed?

[@iamwickedz]

+CrashCourse this video is missing from the crash course physics playlist!

[@Holobrine]

There is a way to deal with gravitational potential energy that isn't relative. It comes from the fact that, using E as all energies other than potential, Ei + PEgi = Ef + PEgf. That can be rewritten as Ef = Ei + PEgi - PEgf. If we expand PEg we get Ef = Ei + mghi - mghf, and then using the distributive property, Ef = Ei + mg(hi - hf). So basically, gravitational potential energy is more about a change in height than some abstract quantity associated with a certain height.

[@hanro50]

Who here is cramming for a physics exam tomorrow?

[@keralagebre]

Great! I liked your way of presentation.

[@emaanfarrukh1719]

This video is really helpful! I couldn't understand this topic even after 3 times revision, but just a 9 minute video did alot!

[@jaydupree418]

You're amazing, you could talk nerdy to me all day.

[@nickalater]

Thank you so much, you summarized everything I've been "trying" to learn for the past month in a 9 min video. You're the best!

[@abemisty]

Hi how are you and this video was so amazing keep up the good work love you

[@Cafetos0777]

The puns are strong in this one haha

[@AKMemon-hy1ym]

No!

[@ahmedadeel2246]

My fave crash course video - bets explained but it stands out due to the rihanna reference at the beginning

[@FirstRisingSouI]

Finally we start getting into real physics. But you forgot to mention the gauge invariance of gravitational potential energy i.e. you can set its zero to be wherever is most convenient.

[@DocSchuster]

...but isn't it obvious from their shaky assumption that the floor will hold? I never trust the floor.

[@assalane]

but that will introduce the possibility to have negative potential energy. People's head will explode!

[@peksn]

+assalane late

[@lineikatabs]

because forces are not real physics... dude, please.

[@FirstRisingSouI]

***** When I think of physics, I think of momentum, energy, fields, and sources (mass, charge, etc). To me, forces are just a tool for practical use, not anything meaningful.

[@SANKERSGAMING]

This the the sixth chapter of physics plus one in ncert Thanks to explain

[@CHAS1422]

Love the subject, love the humor, love the presentation. ...Great video!!!!!

[@webx135]

It took until college physics for my professors to explain just WHY this information is particularly useful. Basically, you have all your forces, masses, distances, speeds, etc, all combined in such a way that you get a number that remains constant. This makes calculations far easier, and you can back track to get other values that may be a pain to calculate. For instance, if you are calculating the speed of a roller coaster at the bottom of a hill, then without work-energy theorem, you would have to do a vector integral to add up all the forces on the car at every point in time. With work-energy theorem, you know that the potential energy at the top of the hill is m x g x h. At the bottom of the hill, all that potential energy is now kinetic energy, which has the formula 1/2 x m x v^2. Since energy is conserved, you just have to throw them together. mgh=0.5mv^2. This simple equation takes into account all the changes in force over all time, but is astoundingly simple, because we are able to relate the properties of a system to a value that remains constant. This may not seem like a big deal, but it really does go far in simplifying everything. Especially fluid dynamics. Though in fluid dynamics, we use a similar idea called "head". Its units are length. It is essentially energy of raising that particular fluid that distance. But this is also constant (unless there is a pump), so you can convert between velocity, height, and pressure fairly easily.

[@arwacloud2736]

when i say work what's the first thing that comes to your mind ? me: RIHANNA

[@samehabbadi8243]

I wonder how is it that easy for you to provide that much of information in a short time! Thank you :]

[@itZMySound]

Shouldn't Hookes Law for a spring be F = - k * x ( k>0) Since the direction of the restoring force is the opposite of the displacement? Otherwise you should write the equation with vectors..

[@DocSchuster]

Since it's not a vector equation, it really is just a statement that spring force is proportional to distance stretched or compressed. I find that, although I teach the negative sign and full vector notation, many students don't immediately grasp that a minus sign means just "the other way." This series is trying to be as clear as possible, so they left that out. In my opinion, it was the right decision for the time allowed.

[@pksir5017]

The graphics of ur videos r so... Amazing. The teachers clarify everything in less amount of time effortlessly... Also your channels contain vedios for almost everytopic.... Cheers ☺️ to one of the best channel Guys u r doing a great work thanks a lot

[@MindLessWiz]

I absolutely love the pedagogical approach in this course. Wonderful stuff!

[@Lowerc09Se]

what is the relationship of power and energy to work?

[@mariajappinen3931]

Really well made!! Thank you for your input and energy. But what a shame to miss a lot because it is way too fast!

[@aldwinvicente3490]

I wish there are explanations on how the formulas were derived, like why is it x^2 for the equation of the potential energy of a spring? Like, seeing the whole thing and how it would apply in the real world and why the formulas are such intuitively rather than just following a formula and solving.

[@rushikaasureshkumar]

actually speaking, i love it ,simply love it :)

[@progunner126]

Thank you

[@interiortruth5342]

The animations are stunning 💜 I wonder what they use to create such beautiful graphics. 😁

[@OzwalR]

I still remember learning that P=F*v when I was taking a lesson on aerodinamics in a Fluid Mechanics curse after the teacher stated that the power to keep a plane in flight was the Drag force times the velocity of flight, that was a really interesting thing I had never though before

[@ladidakalana4233]

Tomorrow Physics Exam!!Hope this will help!

[@karamhassan6884]

You literally summed up three chapters from my Cambridge IGCSE physics book in 10 minutes.

[@FocusMrbjarke]

I need some energy to I finally get to work and get the power I deserve

[@frankschneider6156]

Or you could just have a Red Bull

[@seandafny]

+Frank Schneider lol this comment section is surprisingly funny

[@GrieveCreations]

God I love this channel. It's a great review, but being out of school for a while I now have a genuine interest in learning as much as I can.

[@AdamSmith-kl1rs]

I know all this stuff but I come and like just to support the channel :)

[@jayanthgowda6897]

Adam Smith that's just bcoz the way they present..........😊😊😊😊😀😀😀😀

[@legacybeats7076]

good for you

[@lens_in_wilderness]

anyone will understand power well if the teacher will be so beautiful and smart.

[@gatshenindlovu8224]

Very informative and detailing.

[@KannikCat]

"Are you thinking about it? Good!" :D Love all the annotations (and puns) in this video!

[@mhsstudent4109]

Only gay people like those kind of puns

[@eliyasshaikh4491]

0:07 is that rihanna on the wall ?

[@himanivachhani5575]

Oh my god yes 😂😂😂😂👌👌

[@amiteshpurohit261]

i never understand a single word in physics ever but now i am able to understand thankyou

[@ClearlyImAKong]

The day after I have my work and energy test...

[@adammma1892]

Great video, perfect revision for my GCSE physics

[@werwolfisddoof]

work work work work work you see me doing work work work work work work lalalanananannanannananan physics

[@Breyerlover4ever23]

4:57 So, if the book doesn't have any GPE anymore, and it's not moving (so it wouldn't have kinetic energy), what energy does it now have? Is it just potential energy and not GPE?

[@charndelier5316]

I therefore conclude that you can't crashcourse physics.

[@aurorajarvis5502]

I know people say this goes over their heads but this is such a great primer before you get to the subjects in class

[@rileypurcell2159]

Oh jeez. I was living in blissful ignorance until you brought up exams :(

[@saeedbaig4249]

6:06-6:16- Was.. was there a derivation I missed? How did she get from Hooke's Law and W=Fd to the potential energy of a spring?

[@believe3942]

She explained better than my physics teacher 😂

[@KisemboPhysicsAndMath]

I looove this.... Well, it's alot of information in a few minutes, probably this explains the name of the channel, Crash course. Thanks though team crash course.... This z great work, great set up, great illustrations.... Keep it up. As an owner of a tutorials KZbin channel, I'm greatly inspired to up my game too.....

[@samimas4343]

thanks to you, I ruined my pen.