Which type of friction occurs when an object is at rest relative to the surface?

Which type of friction occurs when an object is at rest relative to the surface?

• A. Kinetic Friction
• B. Static Friction
• C. Rolling Friction
• D. Centrifugal force

Answer: (B)

Static friction is the friction that prevents an object from sliding when it is at rest relative to the surface. It acts to oppose the tendency to motion and can adjust up to a maximum value to keep the object stationary. When an external force tries to move the object but isn’t strong enough to overcome that maximum static friction, the object stays at rest because static friction matches the demand. If the force were large enough to exceed the maximum, motion would begin and kinetic friction would take over. The other options don’t describe friction at rest: kinetic friction occurs when there is sliding motion; rolling friction relates to objects that roll rather than slide; and centrifugal force is not a friction type but a perceived force in rotating frames.

Static friction is the friction that prevents an object from sliding when it is at rest relative to the surface. It acts to oppose the tendency to motion and can adjust up to a maximum value to keep the object stationary. When an external force tries to move the object but isn’t strong enough to overcome that maximum static friction, the object stays at rest because static friction matches the demand. If the force were large enough to exceed the maximum, motion would begin and kinetic friction would take over.

The other options don’t describe friction at rest: kinetic friction occurs when there is sliding motion; rolling friction relates to objects that roll rather than slide; and centrifugal force is not a friction type but a perceived force in rotating frames.