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Tuesday, January 22, 2019

UNDERSTANDING GRAVITATION FORCE AND MAGNETIC FORCE

Question by Chris Halifax Canada age 10
Image result for pic of gravitational pull and magnetic pull

Where does gravitational/magnetic force originate from and why does all matter get pulled by gravity(which is magnetic i believe) yet only certain metals only appear(ferrous)to get attracted to magnets and other forms of matter like wood or plastic,etc don’t seem to get pulled by magnets? chris (age 10) Halifax, Canada ...

Image result for pic of gravitational pull and magnetic pull
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Question by Curious Starvos Kenya age 12


I wanted to ask what the difference is between a magnetic force and a gravitational force. If there’s no difference, I’d like to know how come the Earth’s gravitational pull is able to attract non - magnetic materials e.g human beings, yet no matter how much powerful a magnet is it can never attract non - magnetic(non- ferrous) material.


Answered by:-Chris & Starvos -

Since your questions are roughly the same, I'll answer them both at once. Gravity and magnetism are not the same thing. In fact, they are completely separate forces. Gravity is a force that acts between any two objects with mass. No matter what they are made of, both objects get pulled towards each other just because they have mass. The reason it seems like gravity only pulls you towards the earth is because the earth is so big that the pull from you on it isn't enough to do much to its motion.

Unlike gravity, which occurs between any objects, magnetism depends on specific properties of objects. Magnetism can either pull the two objects together or push them apart, depending on which way the magnets point. Most importantly, it depends on what is going on with the electrons in the material, since each electron is like a tiny magnet itself. Most materials feel very little magnetic force because their electrons act like magnets that are pointing every which way, more or less equal numbers pulling or pushing.

In some materials, the electrons can lower their energy by lining up magnetically into magnetic domains. In each domain, most of the electrons pull and push together, so you can get big forces. In some materials (permanent magnets) the domains can all be lined up so you get really big magnetic forces. If you measure very carefully, however, you find that there are small magnetic forces between magnets and 'non-magnetic' materials like pieces of copper or pieces of wood or people. Some of those 'non-magnetic' things are attracted to magnets and others are repelled.

By the way, only some ferrous materials are magnets, and only a few magnetic materials are ferrous.

Both magnetism and gravity can affect objects at a distance. Both get weaker as the objects get farther apart. This is why you are affected by the pull of gravity from the earth, but not from distance planets. It's also why two magnets may move together if you set them near each other, but if you set them far apart nothing will happen. However, as two objects get far apart, the gravity between them goes down by a factor of four when you double the distance, but the magnetic force goes down by (at least) a factor of sixteen. On the scale of the solar system, with planets far apart, gravity is much more important than magnetism.

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