السلام عليكم ورحمة الله وبركاته
اخواتي العزيزات جدا جدا جدا
عندي سؤاال معطينا الدكتور درجات عليه اذا عرفنا الاجابه وانا متأكده اني انشالله القى عندكم الاجابه عليه
وهو؟؟؟؟؟؟؟؟؟؟؟؟؟؟؟؟؟
لماذا يجذب المغناطيس الحديد بالذات وليس غيره
أي ماهو الذي يميز الحديد لكي يجذبه المغناطيس
ومشكوووورين مقدمااااااااااااااا
على فكره بنااااات أبغي الاجابه خلال هاليومين قبل يووووم الاثنين
النيزك83 @alnyzk83
محررة
يلزم عليك تسجيل الدخول أولًا لكتابة تعليق.
أختي العزيزة النيزك..
أنا أيضا طلب مني الدكتور البحث عن إجابة هذا السؤال في بداية الكورس ولم للأسف ما قدر أحد يجاوب عليه...
ورحنا سألنا دكاترة الفيزياء وما عطونا الإجابة الصحيحة....
شكله دكتورج أهو نفسه دكتوري والله أعلم...
أنا أيضا طلب مني الدكتور البحث عن إجابة هذا السؤال في بداية الكورس ولم للأسف ما قدر أحد يجاوب عليه...
ورحنا سألنا دكاترة الفيزياء وما عطونا الإجابة الصحيحة....
شكله دكتورج أهو نفسه دكتوري والله أعلم...
السلام عليكم
مرحبا اختي..
لقيت لك مواقع كثييييييييير بالانجليزي بس ماقدرت اترجم شي منها للأسف لأن دراستي هنا كلها بالانجليزي :( وماادري كيف اشرح لك واصلا انا مو تخصصي علوم يعني من زمااان مادرست علوم..
بس راح اكتب لك اللينكات ممكن احد غيري يقدر يساعدك..
Why does a magnet attract an ordinary piece of metal? What is the north pole of the magnet attracting, if the metal isn't magnetised itself, and has no 'poles'"?
A good question. We'll have to look at a close-up of a magnet and a piece of metal to answer it.
The reason a magnet will stick to a non-magnetised piece of metal is very similar to the reason why a balloon that you have charged with static electricity will stick to an uncharged wall.
On the left is a piece of ordinary metal. Its molecules are charged, and polarized, which means each molecule has a positive and negative end, which for convenience we will call north and south.
In ordinary metal, the tiny molecule 'magnets' point in all different directions. This makes the entire piece of metal not a magnet, since the magnetic forces inside the metal point in all directions.
Molecules in a metal are not free to move around, but they can rotate if a strong force is applied to them.
Here's a magnet. In this metal, many of the molecules are aligned the same way. They all seem to have their north poles pointing in one direction, and their south poles in another. The electromagnetic fields of force all point the same way ... this makes one end of the metal 'north', and the other 'south'. The more molecules that point the same way, the stronger the electromagnetic force that will occur in the metal as a whole. All the forces point in the same direction.
What can make the molecules in a magnet line up this way? Well, magnetic force causes a 'pull' when unlike poles come near each other, and a 'push' when the same poles are near each other. By rubbing a magnet in one direction along a piece of metal, the magnet's strong force can cause many of the molecules in the metal to align their poles, turning the metal into an artificial magnet.
A natural magnet is a piece of rock that was once deep under the ground, and molten. The earth has a magnetic field, but it is very weak. Ordinarily it is not strong enough to pull the molecules in a metal into the same direction. But when the rock is molten (liquid), the molecules can turn more easily. So molten rock will have its molecules lined up according to the direction of the earth's magnetic field. Once the rock solidifies, the poles are locked in place, and the rock is a permanent magnet.
Only certain metals, like iron, can have molecules with poles that all point in the same direction. These metals are called ferromagnetic. You can make a magnet from iron, but lead won't work.
So how does a magnet cause a non-magnetic piece of metal to stick to it? Well, the metal must be ferromagnetic to start with.
Here's what happens:
When you bring the north end of a magnet near to the unpolarized piece of metal, the electromagnetic force from the magnet makes all the molecules of the metal turn so that the south poles are facing the magnet (because they are attracted to its north pole). This makes the piece of metal into a temporary magnet, and it will stick to the real magnet.
If you leave them together long enough, the molecules in the metal will stay lined up this way, and it will become permanently magnetised.
It works the opposite way, with the same result, if you use the south pole of the magnet instead.
ولي عودة باذن الله ... في امان الله
رنيــم
مرحبا اختي..
لقيت لك مواقع كثييييييييير بالانجليزي بس ماقدرت اترجم شي منها للأسف لأن دراستي هنا كلها بالانجليزي :( وماادري كيف اشرح لك واصلا انا مو تخصصي علوم يعني من زمااان مادرست علوم..
بس راح اكتب لك اللينكات ممكن احد غيري يقدر يساعدك..
Why does a magnet attract an ordinary piece of metal? What is the north pole of the magnet attracting, if the metal isn't magnetised itself, and has no 'poles'"?
A good question. We'll have to look at a close-up of a magnet and a piece of metal to answer it.
The reason a magnet will stick to a non-magnetised piece of metal is very similar to the reason why a balloon that you have charged with static electricity will stick to an uncharged wall.
On the left is a piece of ordinary metal. Its molecules are charged, and polarized, which means each molecule has a positive and negative end, which for convenience we will call north and south.
In ordinary metal, the tiny molecule 'magnets' point in all different directions. This makes the entire piece of metal not a magnet, since the magnetic forces inside the metal point in all directions.
Molecules in a metal are not free to move around, but they can rotate if a strong force is applied to them.
Here's a magnet. In this metal, many of the molecules are aligned the same way. They all seem to have their north poles pointing in one direction, and their south poles in another. The electromagnetic fields of force all point the same way ... this makes one end of the metal 'north', and the other 'south'. The more molecules that point the same way, the stronger the electromagnetic force that will occur in the metal as a whole. All the forces point in the same direction.
What can make the molecules in a magnet line up this way? Well, magnetic force causes a 'pull' when unlike poles come near each other, and a 'push' when the same poles are near each other. By rubbing a magnet in one direction along a piece of metal, the magnet's strong force can cause many of the molecules in the metal to align their poles, turning the metal into an artificial magnet.
A natural magnet is a piece of rock that was once deep under the ground, and molten. The earth has a magnetic field, but it is very weak. Ordinarily it is not strong enough to pull the molecules in a metal into the same direction. But when the rock is molten (liquid), the molecules can turn more easily. So molten rock will have its molecules lined up according to the direction of the earth's magnetic field. Once the rock solidifies, the poles are locked in place, and the rock is a permanent magnet.
Only certain metals, like iron, can have molecules with poles that all point in the same direction. These metals are called ferromagnetic. You can make a magnet from iron, but lead won't work.
So how does a magnet cause a non-magnetic piece of metal to stick to it? Well, the metal must be ferromagnetic to start with.
Here's what happens:
When you bring the north end of a magnet near to the unpolarized piece of metal, the electromagnetic force from the magnet makes all the molecules of the metal turn so that the south poles are facing the magnet (because they are attracted to its north pole). This makes the piece of metal into a temporary magnet, and it will stick to the real magnet.
If you leave them together long enough, the molecules in the metal will stay lined up this way, and it will become permanently magnetised.
It works the opposite way, with the same result, if you use the south pole of the magnet instead.
ولي عودة باذن الله ... في امان الله
رنيــم
الصفحة الأخيرة
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