I got the answer.Shah 72 said:
Friction is a force that resists the motion of objects when they are in contact with each other. It is caused by the roughness of surfaces and the interlocking of microscopic bumps and ridges on those surfaces.
Friction is typically measured using a device called a tribometer, which applies a known force to an object and measures the resulting resistance to motion. The unit of measurement for friction is the coefficient of friction, which is a dimensionless number.
The amount of friction between two surfaces is affected by several factors, including the roughness of the surfaces, the force pressing the surfaces together, and the type of material the surfaces are made of.
Friction plays a crucial role in many everyday activities, such as walking, driving, and writing. It also helps to keep objects in place and prevents them from sliding or slipping. In industrial settings, friction is used to control the speed and movement of machines.
Friction can be reduced by using lubricants, such as oil or grease, to create a slippery layer between two surfaces. Additionally, using smoother surfaces and reducing the force pressing the surfaces together can also decrease friction.