The discussion centers on the concept of static friction, particularly its maximum value when an object is on the verge of sliding. The maximum static friction force is proportional to the normal force, represented mathematically as f_s^{max} = μ_sN. When a person in a rotor experiences changes in angular velocity, the normal force alters, affecting the maximum static friction force accordingly. If the rotor speeds up, the normal force increases, raising the maximum static friction, while slowing down decreases it, potentially leading to slipping if the required friction exceeds the maximum. This explanation clarifies the relationship between normal force, static friction, and motion dynamics.