Magnetism: Crash Course Physics #32
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- Опубликовано: 30 ноя 2016
- You’re probably familiar with the basics of magnets already: They have a north pole and a south pole. Two of the same pole will repel each other, while opposites attract. Only certain materials, especially those that contain iron, can be magnets. And there’s a magnetic field around Earth, which is why you can use a compass to figure out which way is north. In this episode of Crash Course Physics, Shini takes us into the world of magnetism!
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I remember taking physics 2 in college, it was hilarious watching everyone use these right hand rules at their desks during tests staring so hard at the paper while doing these hand gestures. Of course I was too.
got a physics 2 exam tmmrw and I expect much of the same haha
me on my exam next week
i remember school too , but they taught me how to sit straight , nothing about physics i guess mine was a special school .
Its 4am. I have an exam tomorrow and I am crying into a bag of chips cause this just helped me understand all I've been learning all semester. Thank you
For people who are struggling to understand this video because of how fast it is, I use this to study for test and I get A's every time from it so I can help you break some things down and how to understand it better:
1. If things are listed it's probably a key point and should be remembered easily.
2. Pause the video in between ideas to process what she had went over, repeat to yourself key ideas
3. When they show a diagram or chart of some sort, try to study it and go over the things they are talking about in it.
4. Listen to her as if she is telling a story, if makes it more interesting and easier
5. If she talks too fast in an area, reverse it and pause every time you need to remember what she said.
6. If you were daydreaming for a second, reverse and see what she said, it may just be important.
7. If your studying for something I would advise you to rewatch the video 1 or 2 times to get in stuck in your head.
It's called Crash Course for a reason. The information is crashed on you. Why are you complaining about her talking speed when it's actually the point?
no matter what, always is there somebody who complains =\
POV: you're watching this because of corona....
your teacher sent this to you with worksheets
you're procrastinating, instead of watching the video ,you're reading the comments
the comments aren't funny
you're bored now.
facts
yass
They do be spitting Fax doe
Yeah, this was recommended by my teacher
nah my teacher recommended a video that looks like it was made in the 1990's. Im here because this ones better than that video
If you want to get deeper into the physics, the magnetic field is actually the electric field within another frame of reference, according to the rules of special relativity. Einstein's theory fundamentally linked the two, and electricity and magnetism became one and the same: electromagnetism.
IMO this is her best video. Clear explanation, spoken clearly and not too fast or slow. So good even I understood... eventually. Great job!
People were giving me weird looks in the library. One man asked me what I was doing, I simply explained physics homework. The puzzled look he gave me was priceless
I haven't watched crash course in a long time, this is the first time I've seen this woman, and she's great :) time to binge watch crash course haha
These crash course videos are lining up perfectly with the AP Physics 2 topics......too perfectly
Emily Tang lol that's cause they are following the curriculum. It says in the series description. They're falling back for my class though. The electrostatics were going good, but now the videos are coming out too slow to help me through my class...
There is something about your voice that is hypnotic cause I keep listening after I find out the information I was looking for, great job as always
This was really a crash course. I have been searching for such a video for hours, finally I got one with magnetic force on a particle and it's formulas. Great video pls keep making such videos 😃😁
Crash Course Mathematics, please
Yes please!
Dorotheu Ximenes de Farias specifically calculus AB
shut up and take my money
BoB ok :D
Omg yes Please please pleaaase!!!!!
Back 50 years ago on February 14, my physics prof. told us the Valentine day story of a couple called Bev and Bil (the magnetic forces of charge and current). I thought it was pretty stupid at the time, but 50 years later I still remember it.
do y’all know the answers to my science homework
This video was so well constructed, now I have to find all of your other videos because you've explained this so well. Time to learn! Thank you!
Love the video. Very informative!
I am currently in the process of experimenting with magnetic fields, and also high frequency sound waves. But understanding is key here and going back to the basics has proven more helpful then anything. Once you learn the basics of how energy works. Then as a human being you can manipulate that energy to your will.
But... but... what *is* magnetic field?!?!
malignor 5:04 hahahahaha. Doesnt make sense to me either. Not that ive tried really to wrap my head around it
malignor think of it this way: a particle is something that has a value at a single point in space, where a field has a value at every point in space. In this case, we're dealing with a vector field, so every point in space will have a vector associated with it that represents the strength of the magnetic field at that point.
I know you're joking but I find it fascinating people actually questioned the nature of magnetic fields but the same people never questioned "what is an electron?".
In field theory, magnetism is a distortion in the ever-present element of the universe known as the magnetic field. In the same way that gravity is a distortion of what is known as space. Does that help?
Its a gas of photons constantly being emitted and reabsorbed by the electron.
You can show this by calculating the group behavior of a gas of photons is the electric/magnetic field. Its why when you move relative to an electron (electric current) you get a magnetic instead of electric field.
Magnetic and electric fields are not actually two separate objects, they are actually just two parts of the same gas of photons. Which part you see more of depends on the frame that you are moving relative to the electron.
So electric/magnetic field = light bouncing around
WAIT SO THE SOUTH POLE IS TECHNICALLY THE NORTH POLE
dAdDy CLaUs iS iN aNtArCtIcA
The FBI lied to us again
@THe pUmPkIn ,RuLeR oF iLlUmiNatI ConFirMed your part of area 51 mission,cover blown
You guys are awesome, just wanted to let you know. Thanks for everything!
I thank the Graphic Team.. Wonderful job.. :) The lecture goes so comprehensive wit the graphics.. Makes easy to understand
If she was my teacher for physics in high school I'd have a PhD in quantum physics now
What a lesson! Thanks. You saved much of my time.
Thank you so much for this! Very helpful and informative.
Thank you so much for this I am taking this class next semester and I will be looking at your videos for guidance
Thank you, it was really helpful and I really enjoyed it😊. thank you Dr. Shini.❤️
Love the videos you guys make! It's so easy to understand!
4:30- can also be found out using Fleming’s Left Hand Rule, from what I learned.
Once again, Crash Course is a lifesaver. Thank you for saving my physics grade 😂
As my physics textbook neglected beeing produced with the intro pages on magnetism, this is very helpful
At least I know where my missing Giancoli went.....
Fuckin' Magnets, how do they work?
Jim James Was searching the comments for someone who'd post that lol
When particles are in relative motion, they induce a magnetic field. Remember that, even though electrons move at drift speed, current travels near the speed of light which means Special Relativity takes place. The magnetic field causes, according to Maxwell's fourth equation, a changing electric field that will induce a magnetic field around a close loop. All particles have an intrinsic property known as spin that defines its magnetic properties, all of which are caused due to relative motion. It may have spin angular momentum (on its own) or orbital angular momentum (such as electrons orbiting nucleons). We mostly look at electrons because their magnetic dipole moments are thousands of times greater than protons or neutrons. Before I move on, in quantum physics, we can only measure one component which are quantized. For the z direction, the spin / orbital angular momentum is proportional to its spin. For an electron, through experimentations, half of the time an electron will have a downward dipole moment, and the other half of the time an electron will have an upward dipole moment. Thus, we conclude that the spin of an electron is plus or minus 1/2. When the electron is spin-up, its spin is +1/2. When the electron is spin-down, its spin is -1/2.
The magnetic dipole moments are vectors and thus have an associated direction. Due to random disperse of electrons in all different directions, they tend to cancel out making most materials not magnetic. Let's look at Chemistry for a second at electron orbitals. Remember that electrons like to pair? Spin-up electrons like to pair with spin-down electrons; that's how bonding happens. Materials are magnetic only if the combination of all the magnetic dipoles line up to produce a magnetic field, and, as you can tell, this would never spontaneously happen. However, due to chemical properties, it is possible for some materials to be permanently magnetic while others could only be temporarily magnetic.
There are three types of magnetic materials. Let's start with Diamagnetism. This occurs when most of the electrons are paired up in a material. This is the weakest type of magnetism, and all of us (you, me, wooden chairs, etc) are diamagnetic because our electrons are, for the most part, paired up. Have you ever seen a frog levitate due to magnetism? That frog is experiencing diamagnetism. Basically, an external magnetic field is applying a magnetic force on the object away from the source of the magnetic force. That magnetic field induces the electrons in the material to line up, causing it to be magnetic. However, the magnetic field induced in the diamagnetic material opposes the external magnetic field. This pushes the diamagnetic material (e.g. the frog) away to a less magnetic field (like the air). However, diamagnetic materials are only temporarily magnetic. Once you remove the magnetic field, diamagnetic materials lose all magnetic properties.
Next is paramagnetism. Remember what I was saying about unpaired electrons? This is why some elements like the Noble Gases or sodium ions are least magnetic because they have a stable set of paired electrons. Surprisingly, this shows that carbon is more magnetic than fluorine (interesting organic properties). However, if we look at the elements where there are the most unpaired electrons such as the rare earth, actinide, or transition metals, we can see that they are in between full sets of electron orbitals and thus have TONS of unpaired electrons. (Look at iron! It's in the middle of the transition metals, and even though it has 4 levels, it has 4 unpaired electrons hidden in the 3rd level which resists bonding!) Again, an external magnetic field can orient these unpaired electrons to make such materials magnetic and induce their own magnetic field. However, unlike diamagnetic materials whose magnetic fields fight against the external magnetic field, paramagnetic induced magnetic fields actually add up with the external magnetic field to attract to a higher magnetic field. However, like diamagnetic materials, once you remove the external magnetic field, the paramagnetic materials lose their magnetic properties. This explains why you can't make permanent magnets out of most elements like carbon or oxygen.
The last class is ferromagnetism. Ferromagnetic materials are a special type of paramagnetic materials in that, once an external magnetic field is applied, the dipole moments permanently line up forming a permanent magnet. Ferromagnetic materials are typically materials like iron, cobalt, nickel, germanium, and several other materials. This is because their materials are typically arranged in domains. Each domain has their dipole moments arranged in a single direction; however, each domain faces a different direction causing their to be no net magnetic field normally. Once the external magnetic field is introduced, these domains in iron or cobalt line up resulting in permanent magnets. One final note is that increasing the temperature will cause a material to lose its magnetic properties due to quantum effects, but I'm sure you can imagine that increasing the temperature would cause dipole moments to move in all sorts of directions which would ultimately lead to lose such magnetic properties.
What I have just explained is why magnets exist in the way they do. If you want to understand how magnets attract, I'm sure you can easily deduct that from this video. A magnet produces magnetic field lines, similar to electric field lines. Once a magnet detects another set of magnetic field lines, they either repel or attract like charges. Magnetic field lines come out of the North end and come into the South end. (This explains why magnetic monopoles can't exist. The field lines are always coming in from somewhere and coming out the other end. When you cut a magnet, field lines regardless come in from one end and exit the other end.) So when you place a North next to a South, the field lines of the North want to come into the South, so they push toward each other. Similarly, a North and a North are both pushing their field lines away from each other.
Is there anything else you would like me to explain or clarify? I apologize if I lost you somewhere.
Obito Sigma and How long did that take you to copy and paste from the internet? LOL :D
Xavier Underdog LOL! I'm the smartest Juggalo in the world :D
That doesn't explain why they exist for you to fully explain it you must understand Einsteins Special theory of relativity.
Thank you for this amazing explanation and the joke was really funny 😂
i needed thiiiiiiisssss right now !!
Nobody who wasn't already an expert in this field could watch this video and make any sense of it.
so in other words magnets how do they work?
basically what the whole series is
Patrick Melody I dont necessarily understand the variables specifically, but I understood this concept back in the 4th grade when we did electronic wiring experiments.
i'm not an expert and infact am still in highschool(think thats what americans call it) and i understood this perfectly
This is a physics course. Physics is generally a high school level course in the US, some countries might be different. You don't have to be an expert to understand this, you just have to know some physics (I.E. watched the other episodes)-- and have a high school level education.
wow this is so coherent! thank you!
That is really helpful, thanks a lot pale!
"No, you dunce, she means magnetism!"
"... magnets are cool, too"
"Point your arm..."
*Uses Fleming's left hand rule instead*
*Feels like the smartest person alive*
Thanks for this video!
Great video... Entertaining and informative. 🌞
My teaacher needed 4 lessons to explain all this, and i still didnt get it. 9 minute video, and here i am, ready for the exam.
People who are struggling to understand her coz maybe she is a bit too fast, tryna play the video at speed 0.75
It helps! Btw, she is acc amazing
thanks alot that actually helped alot
Cool stuff.New look Crashcourse.
"All you have to understand is this" `*JAZZHANDS!*
hidden knowledge: our bodies are magnetically designed with positive and negative sides- front and back, side to side. this channel isn't really sharing much real wisdom just a bunch of theories and distraction. I'm actually going to unsubscribe because most of what was said was untrue to me- also insurance is a fraud
liked it cuz it was funny
I'd like to know the very fundamentals of magnetism.. in particular the particles that make up magnetic field as well as info on why it moves from north pole to south, and other interesting facts.. I'm guessing it has something to do with electron spin and perhaps positive and negative charges.. also knowing the exact principes of how iron ore is magnetised (does it reposition electrons in a certain patern..?) and the underlaying corelation between magnetism & electricity.. it would be nice to have simplified explanation of magnetism in how it interacts and affects particles, and what particles are involved.. also if it has any relation to quantum mechanics. I'm curious about these things because it seems most of videos about the subject of magnetism only explains what is a magnet (as an object) and how its magnetic fields interact with other fields.. for whatever reason people refrain from explaining most important thing of "why it works the way it does".. it's the same thing people do with gravity, they specify what gravity is, but they fail to explain the very fundamentals of how exactly it works, cause after all saying that "mass warps spacetime which creates gravity" doesj't really explain why :-)
Nice job, way better than the dork that used to do crash course
This series has saved so many students
This is one of the few people I've heard pronounce Ørsted's name at least fairly correctly. She came really close!! Which is awesome
She explains it really well =)
Nice lecture. It was very helpful☺
i love this channel sooo much
Thank you beautiful human beings for the knowledge.
Thanks for this video to help me with my presentation about magnets
Just me or has the animation gotten wayyyy better?
Thank you SOOOO MUCH you helped me with my homework
Lessons worth Half of a semester in one video. Brilliant.
Rosie Rose Are you kidding me that's just 6th grade portion
This couldn't have come at a better time. I have an AP Physics 2 test tomorrow on this.
Evan Hebner what's ap physics?
Evan Hebner I'm just wondering
James Henderson Advanced Placement. It's a US version of hard college-like classes in high school. Sort of like IB classes.
good luck mate
Evan Hebner Same man.
Perfect, I was struggling to get to sleep but now I'll be off in no time now that I've found this video
The direction of the current is from + to - or from - to +? I know that electrons flow from - to + but there is this think called technical directoon or something like that which runs opposite
Sorry if I have missed something here but at 6:01 can someone please explain why the magnetic field is not uniform and is elongated on the side of Earth that is facing away from our Sun?
I think you just helped me get a good great on my midterm thank you ^_^
Aren’t the electrons flowing the wrong way in the battery at 2:47? It should be Anode (-) to cathode (+), right? It’s going from positive to negative in the animation.
It's kinda handy (BADUM CRASH) Me: Jimmy bring daddy his shotgun
Crash Course Coming in the Clutch! Magnetism test tomorrow lol
Waddle literally just had my test a day ago and struggled so much cause our teacher is not very good at explaining the concepts
cool! waiting for you to explain Maxwell!
these videos are perfect for my E+M class! just get the key points and then apply these concepts with math and boom! 4.0 GPA!
so can you create a magnet by churning molten iron at a high enough temperature that the electrons can move between each atom of iron? aka our molten core in small scale?
Except the 1st right hand rule other 2 were unkown to me. Thanks a lot for this video ma'am
"Foolish humans. Sending a metal man to stop the master of magnetism."
That was intense :)
Very educative. One mustn't get set back by the speed of demonstration since it helps hold the idea. Just watch again until you pick up the art if you're serious to pass. (besides,here v~c) .
Theoria Apophasis channel on YT actually shows magnetic fields in a magnet. I won’t even attempt to explain how, but it worth watching.
What is the thing on the top left shelf? Not the newtons cradle or the bobble head.
Not necessarily having this to be a MUST for it to be here , now or ever , but I was wondering if they would ever add another subject they would make it about geography??? Not forcing though I know they may be having a hard time to do these videos so yeah but in case if they were able to (no pressure) like as a next subject
The more charge the particle has, the stronger the force!
*Rey wants to know your location*
Could you do one on understanding LEDs and how to drive them?
Magnetic field exert force on current and also on charges or moving charges?
👍 Great video!
You sneeze you miss half of the video
Great to see original physics content on RUclips, but I long for the day when "Physics Concepts" and "Physics Measurements" get taught as separate subjects.
That is a good point. Actually, the observations, history, measurements, calculations, hypotheses and applications need to be presented separately and clearly. Academic physics mixes all of them, emphasizes on the hypotheses and ignores the applications. This makes physics look like a belief system.
The way we see magnetism today is similar to how Galvani thought of an inherent animal electricity.
Wer have to move like Volta did here to progress in our understanding of magnetism...and the unification of magnetic and electric particlewaves/waveparticles.
Problem is, the hand rules differ depending upon if one is dealing with Conventional or Electron currents. Electron currents utilize the left-hand rule.
These videos are actually really good after you've attended class but they may be confusing if you're really clueless on the topic.
For the equation F = Q V B sin(theta), what is theta since there is no angle between the wire and B (since this is the equation for a single point charge)
Don't know about US prices but on Amazon in UK you can get magnets and iron filings for under £10, so if you're out of school 'cause of Covid, got a bit of pocket money and you like learning with practical experiments take a look
I feel my coils hummm as i drift through your dark matter.
god forbid we separate and communicate at great distances
to seek our return and one again colaps together as one.
I wish yall could have seen my face at the end of this video. I didn't even know it was possible but I'm even more confused then I was. Bout to take this fat L tomorrow ladies and gentlemen
4:12
Thats what i call a short easily memorable note
I could learn anything with her teaching
awesome ❤👍 greetings from Perú
I'm guessing that, if you could magnetize a weak material, it would rip itself apart inside one pole since it repels itself? Which would bring these parts to the opposite pole and mix the whole thing into tiny separate magnets.
I'm correcting myself: two equal poles will repel each other because their magnetic fields are opposing each other. But logically inside a magnet they have the same direction so they hold together very firmly. On the other hand, where is the line between North and South? Wouldn't that only be on the surface because it's dictated by the direction of magnetic flow we perceive?
Atoms within a metal share electrons, which bind them together. This exchange gives them a tendency either to align together or opposite each other, dependent on the spacing of the atoms. In iron the spacing is such that the atoms align in the same direction (ferromagnetism), in chromium they lie in opposing directions (antiferromagnetism). Magnetising a material does cause it to change length slightly. However, since electrons govern both aspects the bonds holding a material together are always stronger than the exchange between atoms. Therefore a material can never rip itself apart from internal repulsion.
Very informative
love the lego millenium falcon in the background
I hate hate hate when they cut out the time between sentences. There is no time to decode.
louis makoni... Noitdoesn'thelptoaddanotherlayerwhenlearningnewstuff. It is easier to work with spaces. It is the responsibility of the coder. Like computers. It is better to use a mouse than have to learn OS language.
You can pause it. I do pause all the time
They cut out that time to make a shorter video and so people who understood it the first time don't lose interest. You can always pause it. Rapid educational videos are popular because people don't need to understand every sentence to get the jist.
just take some adderall
People don't want to watch 20 minute videos unfortunately. I pause and go back when I didn't understand something
are these videos good for the SAT PHYSICS?
plz do more videos on electromagnetism
good explanation
Thanks Ms. You saved my school's pride