Limiting friction is the friction generated between two static surfaces that come into contact with each other. It is the maximum value of static friction that comes into play when the body is just at the point of sliding over the surface of another body. The laws of limiting friction are as follows:
- The direction of motion and the direction of limiting frictional force are always in opposition.
- The limiting friction acts tangentially to the two surfaces in contact at all times.
- The normal force between the two surfaces and the size of the limiting friction are directly related.
- The material, the type of the surfaces in contact, and the smoothness all influence the limiting friction.
- The limiting friction is independent of the surfaces shape and area.
The formula for limiting friction is F = μN, where F is the limiting friction, μ is the limiting friction coefficient, and N is the normal force. It is important to note that the value of static friction is self-adjusting, while the friction value limitation is not self-adjusting.
