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Magnetic forces

Magnets attract or repel each other through magnetic forces. These forces depend on the orientation of the magnets and their distance from each other. The strength of a magnetic force depends on the strength of the magnets and the distance between them. Stronger magnets can even levitate trains! Understanding these forces helps us use magnets in everyday life. Created by Khan Academy.

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  • sneak peak yellow style avatar for user SecretCoder
    Is there a force which increases when the distance increases?
    (21 votes)
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  • blobby green style avatar for user studyn37
    so what exactly is the difference between an electrical force and a magnetic force?? apart from the units that are used
    (6 votes)
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    • leaf green style avatar for user Luigi
      Hi,
      A magnetic force is when magnetic forces(North and South Poles) interact with each other. This may be shown by movement(for an example: Your refrigerator magnet attracts, moves toward the fridge, and stick onto the fridge) between these magnetic poles.
      An electrical force is when electrons(very, VERY, VERY small particles that produce electrical charges) move and interact with each other(for an example: When you touch a doorknob, you feel a shock because electrons are traveling between you and your hand).
      Hope this helps!
      (15 votes)
  • hopper jumping style avatar for user An Opinionated Dude
    Anyone ever heard of Magnetic Hill, Moncton, NB? If yes, you might have heard that a magnetic force pulls you up a hill, but it's just an illusion. What you see, is a hill, but for real, you're going downhill.
    (7 votes)
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  • aqualine tree style avatar for user Omneon
    But, why does north repel north and south attract north?
    (3 votes)
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    • duskpin ultimate style avatar for user Alexa
      This happens because magnets create something called a "magnetic field" around them. The magnetic field is like an invisible force that extends around the magnet. When two magnets come close, their magnetic fields interact. When the magnetic fields interact, they can either push or pull on each other, depending on their poles.
      (5 votes)
  • aqualine ultimate style avatar for user lucca aiken
    what if a make a metal car and put a big horse shoe magnet infront of it would the car move forward
    (3 votes)
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    • duskpin ultimate style avatar for user Alexa
      Even with a very strong and large magnet, it would still not be able to directly propel a metal car forward on its own. The magnetic force generated by a magnet, no matter how strong, is generally not powerful enough to overcome the inertia and resistance of a car's mass and friction with the ground.

      To move a car forward, you need a propulsion system that can generate a significant amount of force to overcome these factors. In most cases, cars are propelled by internal combustion engines, electric motors, or other types of propulsion systems that convert fuel or energy into mechanical motion.

      While a strong magnet can have a significant magnetic field and exert a strong force on magnetic materials, its influence diminishes rapidly with distance. The magnetic force also primarily affects materials that are attracted to magnets, such as iron or steel, and not necessarily the entire car.

      In summary, even a very strong and big magnet would not be able to move a metal car forward on its own. Other forms of propulsion systems are needed to generate the necessary force and power to move a car.
      (5 votes)
  • sneak peak blue style avatar for user JMP299
    Magnets are amazing!
    (5 votes)
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  • eggleston blue style avatar for user dena escot
    Others (magnets) are so strong that even tiny ones can be almost impossible to pull apart. could you explain this statement more ?
    (3 votes)
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  • blobby green style avatar for user Andy
    If you take two south poles and take them away from eachother does the force increase?
    (3 votes)
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  • blobby green style avatar for user HunterA
    what does the n and s stand for I was just wondering
    (3 votes)
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  • leaf green style avatar for user Chinmayee
    how are magnets created?
    (2 votes)
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    • duskpin ultimate style avatar for user Alexa
      Magnets can be created through a process called magnetization. There are different ways to magnetize certain materials, such as iron, nickel, or cobalt, to make them become magnets. Here are a couple of common methods:

      Electromagnetism: You can create a temporary magnet using electricity. This is how electromagnets work. When an electric current flows through a wire wrapped around a core made of magnetic material, such as iron, it creates a magnetic field. This magnetic field makes the material behave like a magnet as long as the current is flowing. When the current is turned off, the magnetism disappears.

      Ferromagnetism: Certain materials, such as iron, can become permanent magnets. They have tiny magnetic regions called domains that are naturally aligned in a random manner, canceling out their overall magnetism. By applying a strong magnetic field to the material or stroking it with a magnet, the domains can align and create a stronger magnetic field. This process is called magnetization, and it makes the material into a permanent magnet.

      It's important to note that not all materials can be easily magnetized. Materials like wood, plastic, or glass are not attracted to magnets because their atoms and electrons are arranged differently, preventing them from easily aligning their magnetic domains.

      So, magnets are created through processes like electromagnetism or magnetization, either by using electricity or aligning the magnetic domains in a material to create a magnetic field.
      (4 votes)

Video transcript

- [Instructor] Let's talk about magnets and magnetic forces. Magnets are these neat objects that are able to attract metals like iron. Magnets are used in all sorts of things, from holding paper on your refrigerator, to computers, to compasses. So magnets can be used to stick things together, point us in the right direction, and even lift things, and they do this through magnetic forces. If you've handled two magnets, you felt magnetic forces, even when the magnets weren't touching each other. That's because magnetic forces are non-contact forces, which just means they can affect other objects they aren't even touching. Magnets will attract or repel each other, and this attraction or repulsion is a magnetic force. But magnetic forces don't affect everything the same way. Otherwise, a magnet would stick to you, not just a refrigerator. In this video, we're going to talk about the magnetic forces between two magnets. So why do magnet sometimes attract each other and other times repel each other? Well, this has to do with the orientation of the magnets. Orientation is really just a fancy word for how the magnets are positioned compared to one another. You see, it turns out that each magnet has a north and south pole, but what does this have to do with attraction or repulsion? Well, as you may have heard, opposites attract. So, if you face the north pole of one magnet to the south pole of another magnet, guess what? They will be attracted to each other. But if you turn one of those magnets around so that you have two north poles facing each other, they will repel. And the same thing would happen if it was two south pulse facing each other. So the direction of the magnetic force completely depends on the orientation of the magnets. Orientation, though, is just one thing that affects magnetic forces. The strength of magnetic forces depends on a couple of things. For one, distance. If you've ever held two magnets, you may have noticed that when you move them closer, they seem to almost jump together. Or if you try to push two light poles together, they get harder and harder to hold together the closer you get. This is because magnetic forces depend on distance. The closer the two magnets are together, the stronger the force between them. So, as the distance decreases, the force increases, but the farther away they are, the weaker the magnetic force is. So, distance increases; force decreases. The other big factor that affects how strong a magnetic force is... Well, the magnets themselves. Sub magnets are really weak, like a lot of refrigerator magnets. Others are so strong that even tiny ones can be almost impossible to pull apart. Some of these stronger magnets are even used to make high-speed trains levitate off the ground. And yes, this rectangle is supposed to be a train. While my drawing isn't amazing, the fact that magnetic forces can levitate a train is.