Understanding Coulomb friction
In my latest post, I explore the mechanics of Coulomb friction, focusing on how it affects motion between a body and a surface. I explain the distinction between static and kinetic friction, describing the force thresholds required to initiate movement and the constant resistance during sliding. Initially, when a force P is applied to a stationary body, static friction arises, counteracting P up to a maximum value defined as F_{max} = \mu_s N, where \mu_s is the coefficient of static friction and N is the normal force.
If P surpasses this maximum static friction threshold, the body transitions into kinetic friction, where the opposing force is given by F_k = \mu_k N, with \mu_k being the coefficient of kinetic friction, which is generally lower than static friction. In this phase, the body moves under a constant opposing force due to kinetic friction.
A more complex case involves tipping, where the applied force P, in combination with the body’s weight mg, can cause one side of the object to lift off the surface, concentrating the normal force at the tipping edge. This results in an impending tip, distinct from slipping, as the body may rotate around the contact point.
For more insights into this topic, you can find the details here.