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I know that this is a total novice question. When I push a book from point A to point B, a force is applied by me. The book has mass and some acceleration was also achieved in this example. I recently read about the fundamental forces of nature. They included Gravitation, Electromagnetism, Strong interaction, and weak interaction. I have no deep knowledge regarding any of the 4 forces. A simple explanation would be appreciated. My question is :

In the act of pushing a book, which of the 4 fundamental forces of nature come in the picture? Which one force could I relate to this event?

Qmechanic
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3 Answers3

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The electromagnetic interaction is the main interaction in pushing the book , as all matter is composed of atoms and molecules whose interaction to other atoms and molecules in bulk matter ( your hand on the book) goes via the electromagnetic interaction.

It is the electromagnetic repulsion ( plus Pauli exclusion principle but it is another story) that keeps the book on the table. The electromagnetic interaction leads the biochemistry and transfers energy to your muscles to be able to transfer energy to the book.

At the classical observable level it is gravity, and electromagnetic interactions. The strong and the weak are effective at small distances where a quantum mechanical framework describes all four interactions ( almost, as gravity is not yet definitively quantized)

anna v
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It's certainly not gravity (your mass is too low), and the strong + weak interactions have very short range. So by elimination, it's the electromagnetic force. This is the same force that governs interactions between atoms.

With the exception of gravity, every force you can see in ordinary life - e.g. the force that holds your body in one piece, the force that prevents the book from falling through the table - is due to the electromagnetic force.

Allure
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When you push a book across a table you will feel that there is friction resisting your push. Friction is what happens when microscopic bumps on the book and table collide. These collisions are ultimately electromagnetic.