In daily life, people often put in the side of the refrigerator some cute little thing to modify them.
We all know, these small objects can be attached to because it has a magnet on the fridge.
According to our experience, in the absence of any intervention, the magnet can be attached in the side of the refrigerator for a long time, or even lost for decades.
So the question is here.
The side of the magnets in the refrigerator.
The earth's gravity pulls it.
Therefore, magnets must have to overcome the gravity of the energy.
Then its power come from, let's start by analyzing the stress state of magnets.
When profile fridge magnets are attracted to, it is static.
According to Newton's first law of motion, static state object is zero outside.
Through a simple analysis, we may safely draw the conclusion that, in this state, magnet will be affected by the four forces, namely, magnet and electromagnetic force between the refrigerator side (
This is two forces)
And in the refrigerator, the earth's gravity and magnet side, between the four force opposite to each other, balance each other, so the magnet is static.
Therefore, we may draw a conclusion that: 'was the side of the adsorption in the refrigerator magnet, and won't fall off for decades.
'this kind of phenomenon is the force balance, and in the end is caused by the gravity and electromagnetic.
Forces between the result of competition, so the magnet electromagnetic force come from?
Here, let's talk about a simple science.