Introduction to magnetism | Physics | Khan Academy

Courses on Khan Academy are always 100% free. Start practicing-and saving your progress-now: www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnets-magnetic/v/introduction-to-magnetism
An introduction to magnetism. Created by Sal Khan.
Watch the next lesson: www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnets-magnetic/v/magnetism-2?YT&Desc&
Missed the previous lesson? www.khanacademy.org/science/physics/circuits-topic/circuits-with-capacitors/v/dielectrics-capacitors?YT&Desc&
Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to Khan Academy’s Physics channel: kzbin.info/door/0oGarQW2lE5PxhGoQAKV7Q
Subscribe to Khan Academy: kzbin.info

[@dalsenov]

I heard that people of Magnesia were very attractive.

[@apowers7783]

Hence my ancestors being magnesian.

[@Daisy-nd7iw]

😂😂😂

[@newbooksmell4163]

I don't know, they did some shady stuff; personally I find them repulsive. :|

[@blakezabala3846]

I heard this joke and I wanted to die :|

[@paralyzedmite3464]

Lol

[@anaavg]

Y'all need to stop complaining. If Sal's rants really bother you, then you have so many other wonderful videos to choose from on KZbin and textbooks that you can probably find cheap, or free. Khan Academy is a blessing, and you're all here for a reason, so just appreciate it, or move on.

[@sritadipatri]

I agree

[@malarganeshamoorthy3068]

Yes you are right dide

[@geenaace5147]

Yep!

[@shreya...007]

I am not bothered by his rants They are educational And so INTERESTING

[@jadentheamazingninja2231]

I agree

[@nickbelanger5225]

Khan you've never let me down. Save me from this test tomorrow!

[@fleshcookie]

" I also looked up milk of magnesia... it was not discovered in magnesia" lol Sal cracks me up

[@alektad]

Best lectures are those who teach the right people, and not the masses. That's why Sal is amazing. He teacher the right people the right way. Entertaining and very educational at the same time. Haters will always hate and never actually accomplish something. Even though I know all this material and didn't learn it from Sal, I love this video, and this playlist in general, as well as the rest of his playlists too.

[@cherbread]

5 seconds in and i was like: Wow I like this guy

[@glowstonestudioz6498]

I had to revise for my magnetism test. HELPFUL!

[@se6586]

Thanks Sal, truly valuable information you put out, and your videos have always satisfied my curiosity

[@geenaace5147]

I really enjoyed this! Thank you so much for taking the time to create a fun, informative video. Most importantly thank you so much for making your videos accessible to everyone. Greetings from the UK!

[@garytyme9384]

All wrong BTW.

[@erik.with.a.c]

now that universities are shut down, there's gonna be a lot of watching khan academy

[@quiznos]

thank you for your work. physics class is so tough but you dissect this information very clearly. and the videos are very enjoyable.

[@Happily418]

I enjoyed this video. Ty for providing a comprehensible working knowledge.

[@exucuseme]

I can't believe that i understood magnetism Awesome video :)

[@Paulorific]

Awesome video, I like all the little extra tidbits of information you gave like the origins on the word magnetism and stuff. Very cool.

[@garytyme9384]

No it was misleading and incorrect.

[@jacobpursell9330]

I feel like everything he has said was relevant. Y’all just want to complain.

[@laelae3152]

I couldn't help but notice that this was posted 12 hours ago, which is like today... So I'm kind of gasping that I'm not alone in my struggles 😅😢

[@zeld8004]

@@laelae3152 well

[@laelae3152]

@@zeld8004 don't even know what I was talking about then🙌😅😂...

[@ftbballah]

To cut to the chase: begin video at 7:15 and you didn't miss anything relevant to physics.

[@asdifhaosidfj103]

was about to make this comment while being at 6:50 atm but instead thumbed up yours lol. sorry but disliking this vid, i don't dislike many vids at all but hate it when people waste your time, even though i played it at 1.5x speed, you're the reason i need to play it at that speed @ maker of this vid just time waste :/

[@peddiumakanth]

true, they actually make sense from there I agree with you Samuel Eto'o and the part where um.. he gave the info about breaking the magnet and it will still be north and south ok I'm bragging too much

[@Anirossa]

ty

[@rakaan4431]

Samuel Eto'o ty

[@sreeramkumar1900]

Om Namaha shivaya

[@Scry999]

8:35 the separation creates 2 norths or souths nearest to each other.

[@g3rmb0y]

This is the best explanation of magnetism I've found on youtube. Great work.

[@TCTFounder]

5:39 Couldn't it be argued that the Magnetic North IS the North pole of our magnetosphere and it's the Compass needle that is mislabeled? If not, then why? By what logic are the poles of a magnet discerned?

[@fauziyhf9793]

Whoa thanks, it all of this video talks about the essential concept. Thought that concept is basic but necessary to understand.

[@erickgarcia7502]

Enough off about Magnesia!! Brief conceptual topic was explained

[@gamingcentral6624]

You are so good you are doing a work of goodness by giving education for free

[@HeelFlipper8548]

The word Magnets is never the same after you watch Breaking Bad

[@tinayip1220]

cool i need to learn to now know more about it

[@slamnxgirlxjulie]

aw man i wish i would have seen this video when i was in physics..finally makes more sense!!

[@Ashfleigh]

I thought the magnetic South Pole was located near the geographic North Pole? Hence why the magnetic North Pole of the compass needle wants to point to the geographic north since it is attracted to the magnetic South Pole. This is what our physics teacher taught us, and it is in our very old books that way as well.

[@formerlypie8781]

you're right, and briefly goes over that near the start, but its easy to miss

[@formerlypie8781]

about ~4:30

[@spectrum792]

A J You're right in this case. Sal made mistakes in this video.

[@sunanditvashisht5549]

Can u post a video for earth's magnetism??

[@mrhansenable]

MAGNESIUM: From the Ancient Greek, "Μαγνήσια" (Magnesia) (district in Thessaly), where discovered. (from Wikipedia). Good guess Sal.

[@itzKittay]

i love how he starts talking about laxatives.

[@TheGrayChannel]

A magnetic monopole sounds like an oxymoron, but it's fascinating to think that one might actually exist.

[@jimmyti9cer]

this stuff is great fundamental physics review for the physics GRE. thank you very much!!!

[@exotic.9315]

Sir thanks for your explaination you teach nice maths and science

[@football_fanapril2048]

im not even at the age yet to understand this but you make it so clearly I feel like my glasses power awaken

[@iwritechecksatthegrocerystore]

“ When they took a lodestone” Hehehehe Good god I’m a 34 year old father! Why am I giggling at that!?!? Sal : I’m good with your tangents. Hell, like I said: I’m a dad. Most of my life is going of on tangents when i have to answer complicates questions. Carry on!

[@ace7997]

This is a great introduction, thank you so much. If I'm correct, the use of magnets was first in China, when the sailors use early compasses for the merchantile and exploration vessels. Just a fun fact.

[@jaysethi733]

Doesn’t matter

[@materbater5596]

@@jaysethi733 neither do u

[@bushmanwest5109]

thankyou 4 helping me with my science revision

[@haiqaaftab6016]

Appreciable work!

[@blancohoussam6128]

nice video dude, you know that the magnetic compass show us always the geographic north pole, we knew that the magnetic south pole is located in the geographical north pole. contrary, the magnetic north is located in the geographical south pole, which is why the needle of the compass always points true north.

[@mahnoorosmani]

It is very good but it is also a little confusing and complicated

[@sobeita]

These objects - magnetism, magnetism... - These objects... I'm just kidding, these videos are great. Triple integrals are a breeze, now I'll deal with fields. :D

[@manisingh8156]

Thanks a lot!! Im finally aware of..... MAGNESIA

[@jackwoofedtoohard7524]

Tommorw I'm going to 5th grade and I'm gonna learn about this

[@fujiboo2343]

oh yes, im finally older than a random comment-er. I'm in 8th grade. Good luck with 5th grade though!

[@jackwoofedtoohard7524]

Thanks!

[@syedakbari845]

Good luck in 6th grade now lol.

[@MaverickCF]

syed akbari lol😂

[@niknic9703]

Now you’re in HS! Haha

[@SamVekemans]

There was a video made from an astronaut in the ISS about magnets, it's cool how it flip as the ISS travels around the world :)

[@mignonludick6947]

I love Khan academy 🙄but i just dont have time to listen to all the bubbling.. rather write a script and go with it

[@adamroshdy1363]

ikr

[@tadsatbanerjee2802]

Guys like you All Don't deserve a teacher like sal.

[@apowers7783]

Magnets, BIATCH!

[@adamfirth3082]

YEHHH BITCH MAGNETS

[@TheClutch1550]

my god, i can't stop laughing, please send help

[@EclipZeMuzik]

dude you're amazing i love this!

[@futsy7]

You teach very nicely.👌👍

[@johngiardinelli1888]

I am intrigued with ed and the coral castle and eventually study all his material. The adventure will continue. Good job. Being visual in the explanation is easiest for me to understand it all. Good job. Thanks man.

[@fleshcookie]

Sal should do an entire playlist on E&M. I hate it. I hate it so much.

[@yiggytiblnibskin6151]

I watched a video of a guy saying all magnets are actually monopolar and the evidence he had, to me, seemed pretty logical. Now idk a lot about magnetism, but assuming the magnetic field of a magnet looks like a torus, which basically every single depiction of it makes it out to be that way, then if you started with several points oriented circularly around a midpoint, expanded those points while rotating clockwise, and then retracted the point inwards while still rotating clockwise, you would get an image like a spirograph. Which, coincidentally, looks like a torus from the top. And since you would be moving clockwise the whole time to generate the field, wouldn't that make it monopolar?

[@eecsta]

Can you explain how Magneto controls the powers of magnetism?

[@AsiatMacksoud-ef4gl]

Thanks for teaching it's really good

[@shahzadaayub]

Great knowledge but why the rush? Who sets the 10 min mark and what's the logic of it in Education? If you have some neighbouring ideas you feel like sharing, the students feel like listening to.

[@karimmohammed189]

Can you please talk more about how the electrons cause the magnetic field???

[@koolyoh213]

men your the best, where are your calculation on newtonian gravity

[@alicegleku78]

Does powder magnet also has dipoles?

[@david0aloha]

@TutorWizard Actually, they are aligned when you look at it on the earth. In the middle of the earth it's flipped around. The reason is that the earth, like any other magnet, has field lines running through and around it. Imagine a circular line running through the middle of the earth, coming out the south pole, going up around the earth, and going back in on the north pole. That's the magnetic field, and things like needle point compasses will align with that.

[@TheDeviantWitchEtsy]

Sal! Cntl-Z is undo :) Thank you for being alive!

[@MidnightHorrors]

I agree that north pole is really " South Pole" good logic!!!

[@goopop67]

make videos on amperes law,solenoids, and current loops

[@MrZak-rf3vq]

The amounts of times you said “its confusing” made me very nervous about this subject.

[@AClassOldie]

Oh my God I was thinking of Milk of Magnesia from the beginning of the video and he mentioned it around the sixth minute lol, anyway SAL YOU ROCK!

[@RAYz544]

wow! bro u r great it helped me alot

[@gh0stmast3r]

magnets, how the f*ck do they work?

[@BorisNoiseChannel]

we don't know, so it must be God ;-) (btw; its what alien crafts fly on )

[@basmaal-awaja7433]

he sounds like the guy from "the noted anatomist"

[@ravindranathpk]

d explanation worked 4 me..nice work..

[@agricolaterrae]

@TutorWizard Geographic north and south were set before they really understood how magnets worked. So "North" was defined as the end that pointed to the already recognized north. Conventions really don't make sense. Electricity is even more bizzare.

[@schmiigle]

Sal's little Magnesia soliloquy haaahhaa! Such a good teacher

[@from93till]

This video is full of miracles.

[@jexphe2k]

magnetism is just a magnetic substance that was put on an object. everything can be magnetized with the proper condition applied.

[@idiosyncraticidiott5015]

The magnet on the left looks like a smiley face hehe

[@blancohoussam6128]

please i want to know how to calculat the magnetic field and the relation between voltage, tesla,amps, power (watt) and even the quantity of the electricity (coulomb) thank you sir

[@SandeepKumarDashSandeep12]

Sal magnetic north pole is in Antarctica not Canada.

[@rinnegansr5980]

you are wrong just wrong

[@agent475816]

+Sandeep Kumar Dash Yes.

[@CondensedComments]

Why is there a desire for a magnetic monopole; what are it's proposed uses and how is it proposed they operate?

[@harshtanwar6511]

How can you say both magnetic and electrostatic force is same?

[@SteveSmoky]

this is awesome!!!!!!!!!!!!!!!!!!!!!!

[@srishtiparihar960]

nice video keep it up

[@borkiarchives1634]

From where the force of attraction come to the magnet ? How they attract other things?

[@TechLeechastik]

Oh! Here comes sal with his 240p video. LOL. Great video though :)

[@crystalidx]

I wonder if the element kryton was first discovered in Kryton as well, probably.

[@storyiseverything2219]

Does a magnet loose its pull over time?

[@Thibeinn]

A magnetic monopole is an impossibility due to the fact that nature maintains balance and to have a monopole would be to have a thing which is not in balance. There must always be positive and negative, north pole and south pole, action and reaction, give and take.

[@randomrog311]

can understand is very clearly

[@rajinderkumar-ou2qc]

can anyone tell me WHAT IS ANGLE OF DIP...

[@fcmilsweeper9]

Wait so 1. A current induces magnetic field but then later on you learn 2. Changing electric field induces steady mag field and 3. Changing mag field induces steady e-field. Doesn't #2. Contradict #1 since a current is driven by a steady e-field in a wire??????? Any help is greatly appreciated. Thanks.

[@olimanders8020]

its pretty easy but my father forced me to study about it unlike poles attract like n pole and s pole and like poles repel or push away from each other such as s pole and s pole

[@n_gauhar2645]

Isn't it supposed to be 'magnetic south' that is situated at 'geographical north'?

[@MrKshitij23]

at moment 08:38 after breaking the magnet bar i think it should break with S|N;N|S not like S|N;S|N as i have observed that after breaking bar the 2 parts repel each other am i right?

[@GiovaniCeotto]

at 1:33 he is talking about Einstein Theory of Special relativity concerning magnetism and electrostatic forces right?

[@raynali2054]

Magnesium was found in Greece by Joseph Black and Humphry Davy

[@chocokitty7]

I love your voice!

[@pepe371]

.....wierd...

[@beastlt12]

Great Vid. Thanks!

[@danielbautista12able]

geographic north pole is magnetic south pole that's why magnetic north pole of a magnet attracts geographic north pole. when you freely hang a bar of magnet, north pole of a magnet point in north direction..

[@firstnamelastname4752]

6:30 to skip all the preamble.

[@momorgoth]

Thank you kind sir.

[@alec8701]

What is a positive or negative charge??? All I want to know is what is a magnet and why theirs an invisible force not seen in the visible light spectrum the repulses them from each other.

[@jgposner]

I'm a beginner in Physics, I always thought a magnet was created by forcing a bunch of electrons over to one side of the magnet. I always wondered why they didn't simply move back so they were evenly distributed again. But now I know it's because we put all the clockwise spinning electrons on one side and all the counter clockwise on the other. Interesting, I can't wait to learn more.

[@jbragg33]

I think magnetism is caused by to the spin of the _Nucleus_ of the atoms, and not the spin of the Electrons like you said.

[@seanbullis3364]

Well I learned a lot about Magnesia

[@bilalpkriyadh9131]

very good I like these