The force produced when two materials rub together is called friction.

Here's a breakdown:

* Friction is a force that opposes motion between two surfaces in contact.

* Static friction is the force that prevents an object from moving when a force is applied to it.

* Kinetic friction is the force that opposes motion between two surfaces that are already moving relative to each other.

Friction is caused by the microscopic irregularities on the surfaces of the materials. When the surfaces rub together, these irregularities interact and create a resistance to movement.

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