When two surfaces come into contact, the forces exerted by one surface on the other are called

When two surfaces come into contact, the forces exerted by one surface on the other are called

• A. friction force
• B. kinetic friction
• C. static friction
• D. pending motion

Answer: (A)

Friction force is the force that arises at the interface between surfaces to oppose their relative motion or tendency to move. When two surfaces come into contact, the forces exerted by one surface on the other are friction forces. These can be static or kinetic: static friction acts when there is no actual sliding yet and can take any value up to a maximum of μsN, increasing with the applied tangential force as long as the surfaces don’t slip; once the tangential force exceeds that limit, sliding begins and kinetic friction μkN acts to oppose the motion. The term “pending motion” isn’t a standard description of this interaction.

Friction force is the force that arises at the interface between surfaces to oppose their relative motion or tendency to move. When two surfaces come into contact, the forces exerted by one surface on the other are friction forces. These can be static or kinetic: static friction acts when there is no actual sliding yet and can take any value up to a maximum of μsN, increasing with the applied tangential force as long as the surfaces don’t slip; once the tangential force exceeds that limit, sliding begins and kinetic friction μkN acts to oppose the motion. The term “pending motion” isn’t a standard description of this interaction.