Introduction to motion

[PastaIsCrazy1]

Isnt gravity only applied with vertical motion?

[Kricardose]

I am very happy to see the vidoe Introduction to basic physics of motion. Introduces the concept of variable velocity/acceleration after you give this

[bebeheuy]

I Love The Video Introduction to basic physics of motion. Introduces the concept of variable velocity/acceleration It Can Increase My Knowledge

[Mjhond]

Steady I Really Like This Video Introduction to basic physics of motion. Introduces the concept of variable velocity/acceleration

[789123Y]

I never understand that "cancelling out"

[swimmershark]

D is for Displacement, not for Distance.

The first is a vector. The second is a scalar. If you go north 30 miles and then south 20 miles, you end up with a displacement of 10 miles north, but you used 50 miles of gas.

[DeathCreed72]

Thnx ur videos seriously help me alot:)

And i like the fact that we're more important:P

[kaustubhchahande]

Salman Khan should be awarded the Nobel Peace Prize for giving peace of mind to students all across the globe! B-)

(By the way, I am from Nagpur, India)

[MrMachinima2009]

Good teaching but you dont want to assume that some people understand some of the concepts you are teaching. Sometime people want to learn from absolute scratch and when you assume they know certain concepts then they might get frustrated and not learn the content.

[Abrahamkristal]

Damn..I was looking for Motion Graphics lol..



[GreeblyChicken]

You are awesome. Do you live off youtube advert money or are you a paid teacher or something?

[wirelesscps]

i downloaded you ipod app vert good man

[LaughingSeraphim]

I urge you to find a way to type your presentations or work on your penmanship. What you are doing is wonderful, but sometimes the' c' shaped equal signs and such are a tad distracting.

[rwwanon]

18 people would rather see students educated like humans than programmed like a calculator.

[joannafreethinker]

Awesome



[JAJTB]

thank you so much for helping us... school will start in like 2 weeks so thank you, this is a great help for me to review physics so that the ideas will be fresh in my mind when I get to school and I could also have some advantage when school starts. thank you.. I will continue watching your other videos.. thank you again! =)

[BrainiacWorkshop]

The 17 who disliked are teachers. 

[harisbhatti1]

 thanx sal khan u r making every thing very easy thanx mr sal

[feraligatr8]

My physics teacher sucks ass :(

[Nightrazr]

You are amazing and I will keep watching your videos because I fucked up majorly at highschool.

Thank you VERY much for this opportunity to get a better education.

[noshyfication]

I want to thank you for all the physic videos. I had the most horrible physics teacher in high school and now that I have to take it again in college...i am scared lol but my goal is to watch all ur physics videos this summer and teach myself.

no word can describe how i feel about Khanacademy...this is the way to change the world! Thank you!

[NVSBLmonstr]

I REEEAAALLLY like what you're doing with these videos and the site, but you should consider investing in some sort of Wacom tablet or something. Would be much easier to read these symbols than when they're written with a mouse.

[TacticalMatrix]

@Vaylemn

Keep in mind though that velocity is a vector quantity (has a specified direction on top of the speed)

[mileyice13]

I just realized that sal's lessons only work for me when i've been previously taught the topic already, like if it's a new lesson, i don't understand as well. :(

[narcomanel]

"you could kill somebody" ahahaha, thanks for the advice.

[Himlagglol]

I LOVE THIS!!!! IT IS VERY INTERESTING IM MAY BECOME AN ADDICT TO THIS!

[nikkilak]

Speak up, eh?

[NIGHTmayr23]

Just so that people dont concrete the idea of distance being speed multiplied by time it's actually

Speed=distance divided by time

I appreciate what you are trying to do with teaching, so glad I had the initiative to search about this on youtube. thank you.

[FallofDarkness55]

red pill=physics and blue pill=not having an interest in physics. i choose the red pill. physics is awesome especially when it goes into quantum mechanics and eventually theoretical physics.

[hahaumiss91]

im using this to review for my phys exam

[thegreendayfanable]

i thought

speed=distance/time

velocity=displacement/time

and dist. and disp. are different thing

[Vaylemn]

@thegreendayfanable distance over time is implying the change of distance over time, which is the same as displacement over time. Velocity is just a more scientific term for speed.

[Ryanxclarke]

@thegreendayfanable i believe displacement (s) is the same thing as distance

[filmmetoo]

I'm only 4 years old and already I'm completely fluent in all levels of calculus because of Khan.

Thank you.

[PROMTan1]

Physic teachers are idiots except for you sal



[ShadowCrashed81]

@PROMTan1 What about the physics teachers who taught Sal?!

[brazabel]

wooow You are a Good Teacher am Just taking Notes as You are doing this GREAT!!!!!!!!!!!!!!!!!!!!!

[SCIGEEK15]

I LOVE YOU!

[SoReaICru]

Hey, does anyone know what grade these videos are based on?

like for Grade 12, First Year Uni...

[IdiotWithSticks]

@SoReaICru Screw that grade and school shit! Just look for what you want to know :)

[theredmars]

i can't believe you can write so legibly with a mouse.

[Skyrodude]

@theredmars

He uses a wacom tablet.

[MrBigEnchilada]

@theredmars i dont think its a mouse, it's a pen. My teacher also used a program like this one because he didnt want to write on the board and keep erasing.

[LordKaisen]

and guys its not just Physics! computer programming, math, history, etc they're all accessible here which is great! I think everyone should recommend this vid to their profs so they know that interactive stuff like this is out there for everybody, that's really how students should learn too, take the time to sit down and learn by themselves.

[fire9132]

Lol

at the begining " hello I think a welcome"

[LordKaisen]

@mnmsbubbles I can literally record my class and show the world how poorly most students listen to the teachers and put the needed effort to get that A. Maybe I should do that even if its illegal...it will put to rest the stereotype that students fail Only because of poor teachers.

[ultimage7]

Stop blaming your teachers for not learning in school. Damn kids.

[visrant]

Superb!!! I love it when a teacher can make a student smile :) Keep it up Sal...

[raihan093]

If I don't subscribe I FAIL Physics.

[mariavelordi]

you are just so AMAZING!!! thanx a lot!

[lakiroch]

This is great..a good approach to physics from the very basics..i highly recommend khan academy videos for all A/L science stream students!!

Keep up the good work!!

[jonjonjon1370]

Sal, your amazing. Because of you, I learned algebra in 3rd grade, and I get plenty of A's cause of you. Know in 6th grade, I have completed: trig/ pre-

algebra/algebra/geometrey..etc , and know starting physics. Thank you!

[vigneshchelsea]

shit ..i will pay a million dollars for u to teach me

[wwedude007]

all my teachers are amazing but you are among one of the best teachers I have ever seen (I haven't met you) lol.

[kanashiihanashi6]

once again his voice is really charming.....uhhhhhh

[narragansettharco]

Free energy is finaly here!But there are very powerfull forces that want to supress the technology,Get the blueprints for a real Magnet motor free enegy machine at LT-MAGNET-MOTORdotCOM ,Join the energy revolution!

[ryankhan11]

My physics teacher cant teach for shit, n hes stupid too. Thank you so much Mr Khan! I'm a Khan aswell! =D

[tomsk27]

Its just amazing what one person can do for the world.

[Alex75304]

my physics teacher is a dumbass

[lamp23]

I have started a study group with 4 members who will be starting with this video tonight. Anyone is welcome to join us on our teamspeak at 11pm EST (October 4). Check us out at freeuniversity.ucoz.com where you will find links to different chat rooms including the zeitgeist teampspeak 3 server.

[lamp23]

I have started a study group with 4 members who will be starting with this video tonight. Anyone is welcome to j us on our teamspeak at 11pm EST (October 4). Check us out at where you will find links to different chat rooms including the zeitgeist teamspeak 3 server.

[simonrdownes]

Greetings from central Tokyo. Thank you, Sal. I am using your videos to prepare for the MCAT.

[lifeDotGov]

4:30

[chstrphrs]

To the creator of this video, you are a lifesaver! I'm taking Physics right now and my teacher has made it seem impossible. Thank you for this video!

[bnladen09]

..yeah i have learned motion in wikipedia...i like it !! ;D

all what you need about science, physics, art , history, geography and much more ! ..yopeee, i don't need to see our dumb teacher !! lol

[bceng89]

shouldn't a = (delta v)/ t since velocity is chanting over time? if you just leave the v that implies that v is constant which its not

[321boileranimal]

Sal Khan single handedly fixes America's educational system. 

[Pumbrnatrr]

@321boileranimal not only america's but the world's!

[thawestcoast]

I Love You mannnnnn

[xB4SsXb0yx]

hehe my physics teacher is making me watch this for school.....

[vukbui1987]

majority of the physic professors cannot teach for shit, or just simply assholes.

[KirbehsBizzatch]

So... You think this will help me in my AP Physics class? I was hoping to pick up a bit before charging into class so I could get a headstart, and was reading a book to help me do so. If this will work though, I might just switch.

[gokorea1233]

I think Sal should win a Nobel Prize for his amazing contribution and dedication in educating the world : )

[anessenator]

Khan is brilliant. Watching these videos in parallel with a textbook is ideal. One helps to reinforce the other (for me anyway).

[KalishKovacs]

I learnt something in the first 2 mins.

Thumbs up if you did too.

[highlanderdurp]

@KalishKovacs you learnt?

[RoyceRK]

@highlanderdurp It's a perfectly valid word. In fact it is a past participle and past tense (from learn).

learnt - Gain or acquire knowledge of or skill in (something) by study, experience, or being taught.

[KalishKovacs]

@highlanderdurp its the correct word, look it up.

[pokechamp2006]

you sir, are THE man. You've made education simpler and useful. I thank you.

[shabadoooo12345]

wow. i would have done so much better in physics if i had seen this.

[interstitialofficial]

I never intuited division, so the phrase "cancel out" kept me from being good at math for years. They cancel out like matter/anti-matter? Or what? Just saying, "they cancel each other out" like that explains it all, does not explain it at all for those of us who weren't born with the ability to intuit math. This means that a lot of people were nodding their heads to indicate understanding, even though all they were doing was memorizing the steps to take to get the problem right and pass the test

[MarvelsofaLifetime]

It is actually not that difficult once you actually learn and ‘understand’ it. V x 10 seconds divided by 10 seconds – well what is 10 seconds divided by 10 seconds – common intuition should tell you 1; so now it is V x 1. But because that V is being multiplied by 1 and the 1 doesn’t actually change the number you can just get rid of it. I know it is really confusing at first – only a few months ago I was in your same shoes; but just watch some of Sal’s math videos, that should help.

[Monday75965]

thnx man...

[Rayden440]

You should apply for one of those special accounts that allow you yo post more than 10 minutes.

[shemulable]

dude u rock, ur my superstar, u make things so simple to learn

[JESSFALLINGDOWN]

Sal.. maybe these videos are the real cause of grade inflation.. I know they are with my grades! Thanks again!

[joshuaguevara]

"lemme answer that a little bit later,cause once again...you are more important"

LOL u rock sal!  <3

[TheKarlock]

Oh my god yeah this guy might ramble just a tad, but it is always on a valid and important idea or piece of information. He is amazing at breaking this down.

[MarvelsofaLifetime]

I love taking all of the formulas and drawing them out on my own. Because I have the same type of program that he is using, and it really helps me to make sure that I don't just have the equations memorized, but instead, to actually understand them. Great stuff, I love Physics.

[thirstaid09]

just want to say THANK YOU Khanacademy

[YourSexisOnFire100]

just curious what grade level would this be for? because I am taking grade 11 university level physics and I was wondering if this would pertain to that course.

[riteasrain]

@marcuelcajon Guess what? That's what vids are for - PAUSE.... Get it? ;-)

[MarvelsofaLifetime]

@marcuelcajon May God help you...

[TengoNoNombre]

wow, excelente, eres el mejor, y por que no lo haces en espanol? why not in spanish?

[lemonfreshman]

because you should learn english

[xXdaveXsuperstarXx]

THANK YOU!

[energychaser]

Brilliant wish I had this when I was taking my O levels.

[FreedomUSA1]

You are the best sir. I am paying hundreds of dollars to take a college physics course, yet you are far easier to understand - AND FREE! Thank you so much Mr. Khan.

[paulojunior201]

quit the course man !!!!!!!! jesus christ !!!!!

[MrCydia]

@paulojunior201 get a hair cut

[Takyura9]

Sorry...where is the penny be drop at the end? An in______ rising building? (so It will not kill anyone..... Orz)

[Krazykhamini]

i am honestly passing physics because of u

thank you!

[ddfgg42]

why he always whispers to himself

[anu427]

thank you soooo much for these awesome videos....im really learning a lot!!!!!!!

[matthewhhchan0820]

that's why i subscribe you, Mr. Khan! Cuz' yo r the man!!

[ABCba5tard]

hes using a pen dumbass

[FireBenderKwyna]

I wish you taught my class. Our physics teacher is an idiot.

[meraphox]

Same

[Cybernetic]

@FireBenderKwyna  same with mine

[moneybagzkd]

@FireBenderKwyna Mine 2! :P

[NewJDubs]

@FireBenderKwyna He is a good teacher n all but it would really upgrade his videos if he got a writing pad so he didn't have to write with his mouse.

[calvinnewspaper]

@FireBenderKwyna Same here.

[Solereaper21]

@FireBenderKwyna I know how you feel

[xKevox2]

@FireBenderKwyna I think I have the same teacher as you!..

[riashadbro]

@FireBenderKwyna nothing beats my , seriously , not even exxagerating , worst teacher , good guy but CANNOT teach, in english.

[shadodaful]

dude nice handwriting u r the man

[irtgreen88]

He has to use a mouse..so..

[seymorebutters]

Absolutely awesome, thankyou so much for taking the time to make all these videos Mr Khan - I will be watching every single one!!

[newtonsharma]

Which type of software do you use on this video? Love your videos

Thanks for the videos. Very useful videos

[STSCThomas]

i'm not even half way through this video yet, and i already feel smarter...

i hope the whole series is just as sick...

[mstixj]

This guy is saving my hide right now...currently enrolled in a school where we are covering about 1 subject a day. In the past month we have started here with this concept and currently are on Fluids....great stuff keep watching

[MatheusAgostin]

kewl

[jagexownage]

I want to learn physics Please help me out i'm a total begginer and I want to learn this. Message me in what i need to do.

[W4llz4life]

watch the videos lol

[jagexownage]

Um, I Already Studied some books and did a couple of problems and I'm starting to get better in physics.

[hacksign000]

watch all of his videos about physic lol ?

[cskylark9]

i just had a question, is velocity times time equal to displacement?

[Whopzer]

Thank you so much for these videos! You've got everything from the most basic things to the more advanced! This is truly one of the best channels on youtube.

[crumcon]

Youtube should placed this channel in the front page!!!!!!! damn youtube!!!

This is the best channel for students of all ages!!!!

this channel is even useful to 3 month babies

[lwanatt]

@crumcon lol if youtube put this on the front page they would be out of business by the end of the day. You really think people really want to better themselves? People come to youtube for the sole purpose of finding a way to waste a small portion of their life.

[moh199702]

i don't get the canceling out why do they cancel out (the seconds in ex. 2

[bozcro4lyf]

What is the opposite of multiplying? Dividing yes? So if you multiply 7m/s by 5s, you get rid of the s. So your left with 35m.

[TheFrycry]

Never neglect little things coz its not a projectile motion...

[zdon25]

Yes. Boring to someone not seeking knowledge, To the rest of its like chocolate cake

[SimeonBerson10101]

GREAT VIDEOS! THANKS SO MUCH

[shkellyp]

I agree with the last comment. It seems to me in the 1st equation you did not give a vector direction. So iu solved it for the acceleration. Plus gravity is 9.8 m/s per s and since it is known to have a direction it is a velocity.

[ETERNALinstants]

You said in the video Velocity is a vector.

But in the equation you the velocity is equal to 5 m/sec so where is the direction? : {

[alankarmisra]

@Eternalinstants - I'm not a physicist, but based on the video, the sign of the value determines the direction?

[55flanders]

dang that was very perplexing thinking too his mistake....hats off too you

[ETERNALinstants]

referring to me?

[paintedtortle]

Velocity is a vector, but sometimes people leave out the direction and just give the magnitude.

[samadhiatman1975]

You rock. This is so great I can learn this on the net. I appreciate this video and you. Yippee!

[videoofmike]

god I love you

[xxStrykerxx1]

correction , five miles and hour is forward negative five miles an hour is backwards, because when you go negative you go backwards

[Matice21]

sO aMAZING

[nypdaniel]

long live the internet!

[tetiraelian]

indeed

[youvebeenthunderstru]

This is completely unrelated but your voice sounds a bit like Frank Zappa.

[laputahayom]

what program are you using to draw?

[koolyoh213]

paint, you have this when ur using MS os win xp, vista's

[koolyoh213]

and it's MS application prog.

[laputahayom]

thanks

[scorpion8588]

Does anyone know where I can find a free online physics text book with the answers to odd problems? Or something close to that?

[erinashleyx]

wow you're AMAZING, thaaaaank you.

[bregedenz]

thanks dude

[tabasdezh]

you r a starrrrrrrrrrrrrrrrrrrrrrrrr

[djgiohappy]

Thanks man, your videos are very helpful..

[Winsunn307]

You know everything, Sal. Thanks for this, you are King.

[IriquoisPliskinn]

Who called?

[HotActionProductions]

is it snake or is it Dero?

a long time ago, Iriquois Pliskin used to be a human.

[taichisupporter]

I am studying Physics1A in a degree level and your video helps me alot, thanks for uploading it khanacademy.

You will get a great reward for your great work.

[shifterdude647]

awesome vid! thx alot

[Sampson712]

Nice videos man they're really interesting thanks :D

[Aydee2020]

they also teach physics in  'Human Weapon'

[joeclarkin94]

Use a pencil

[sohoist]

A penny dropped from Empire State building will not kill or even unlikely to injure someone.

[cressilia]

I'm guessing he was talking about the rock.

[idster7]

@sohoist i think you're wrong about that.

[allhailkingofthelose]

you sound drunk at the very beggining

[iluvjiyongx3]

omg. i didnt know u had vids on physics too! ur calc vids r a big help and so is this vid! thanks~