Charging by Friction

Friction is the force resisiting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. 

There are a few types of friction:

·    Dry Friction: resists relative motion of two solid surfaces in contact. Dry friction has to categories:

1. Static friction between non-moving surfaces 2. Kinetic friction between moving surfaces.

·    Lubricated friction: fluid friction where fluids seperate 2 solids.

·    Skin friction: a component of drag, forces resisting motion of a solid body through fluids.

·    Internal friction: forces resisting motion between elements making solid materials while undergoing deformation.

When surfaces that are touching move relative to each other, the friction between the two surfaces kinetic energy into heat. Such as when wood is rubbed together, the friction causes a fire because  the kinetic energy transforms into heat. Friction has consquences such as being burned by the fire or objects having performance degradations. Friction comes from electromagnetic forces from two or more charged objects.