Each magnet has 2 faces or 2 ends called north and south poles. It’s so called because if you hang a magnet on a thread, its south pole will point north. That phenomenon occurs because the core of the Earth is a mass of large and weak magnets. Your little magnet is attracted to the core of the Earth, so it points North. That’s the rule in which direction the magnet turns.
If you keep two magnets facing each other in the wrong direction, they will repel each other, in other words if you hold two magnets rotating at the same South or North poles together, they will repel each other. Try it and see! You will feel like 2 magnets are covered with transparent rubber padding that does not allow them to come close to each other. That invisible padding is called the magnetic field.
Same sign repel each other : We can use curved arrows (called field lines) to draw the shape of the magnetic field around the magnet. Arrows always start from the north pole of the magnet and point towards the south pole. When the same poles are facing each other, the arrows from the two magnets point in opposite directions and the field lines cannot meet. So the two magnets will repel each other.
Only when you put two magnets close to each other and one of the South poles and the other North pole are facing each other will they attract each other. Now you will see that the magnetic field is like a rubber band pulling them together.
Opposite signs attract each other : When a North pole points towards a South pole, the arrows point in the same direction, so the field lines can meet and the two magnets attract each other.
You must have heard of energy. There must be energy for movement.
A stationary motorbike or car will only be able to go when the engine is started, starting the engine is the movement to burn the gasoline contained in the vehicle. Gasoline contains energy and this energy is released when gasoline burns. When the energy in gasoline is released, part of it turns into motion energy. Scientists call the energy stored in unburnt gasoline “potential energy,” and the energy that causes motion after gasoline burns “kinetic energy.”
When you start running, the energy stored in the food is released and partly converted into the energy that causes your running.
So what about magnets? The magnetic field around a magnet contains “potential energy “, and one way to transform that potential is that the way you put two magnets facing each other leads to the way they move.
Everything in this universe obeys a rule. (Why all follow one rule is another question, which is difficult to explain if we do not have complex mathematical knowledge.)
2 magnets will be pushed in the direction of reducing stored energy.
The rule is: where there is stored energy in an object (and the object is not tied up or stuck in a fixed place) , the object will be pushed towards where its stored energy is. consumption. This stored energy will decrease and be replaced by moving energy.
So, if two magnets rotate with opposite poles (the north pole of one turns to the south pole of the other), they will get closer to each other and reduce the energy stored in the magnetic field. They will be attracted to each other, aka attraction.
If two magnets both rotate the South pole toward each other or rotate the North pole towards each other, the stored energy will decrease as they move further away from each other.
So this rule says that the two magnets will be repelled in a direction that reduces the stored energy.
This rule also says that when dropping objects that are attracted to the Earth and fall, it is not due to magnetism, but due to gravity. The Earth is also surrounded by a gravitational field that contains stored energy.
Unlike magnetism, gravity never pushes because gravity has only one dimension. Gravity has no north or south pole.
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Once the two magnets are attached, you need to return some of the “potential energy” back to the field by pulling the two magnets apart. You cannot take energy for nothing in return.
The energy it takes to pull two magnets apart is your energy, and you get energy from food. Vegetables, meat, fish you eat get energy from other plants and animals, or from the Sun. All energy has to come from somewhere.