Question

How friction keep a nail in place in a wood

Answer 1

Friction between the nail and the wood surface prevents the nail from sliding or coming out of the wood. When a nail is hammered into wood, the frictional force between the nail and the wood fibers creates resistance to motion. The nail threads or barbs also aid in increasing friction by digging into the wood fibers and creating a tighter grip. The greater the force applied or friction between the surfaces, the greater the resistance to movement or pulling out of the nail. This allows the nail to stay in place when force is applied, such as when hanging objects or when subjected to lateral forces.