Friction

physics · forces · motion

The grippy force. Friction is the force that resists when two surfaces slide or rub against each other. Without it, you couldn't walk, write, or stop a bike!

Heat from rubbing. When surfaces rub together, friction can create heat. That's why rubbing your hands together quickly makes them feel warm.

Slippery helpers. Lubricants like oil reduce friction by letting surfaces slide more easily, which helps machines run smoothly.

Many flavors. There are different kinds of friction, including dry friction between solids and fluid friction in liquids and gases like air.

Ancient science. The study of friction is called tribology, and people have been exploring it for more than 2,000 years!