I think the correct answer is true. A frictional force is the force exerted by a surface as an object moves across it; therefore, it is considered a contact force. This force is a result of two objects that slides against each other. This value is largely affected by the texture of the surface and the amount of the force that is exerted to each other. It is equal to the product of the normal force and the coefficient of friction. There are to types of frictional force namely the fluid friction and the dry friction. Fluid friction is a frictional force that occurs when a fluid gives resistance to two surfaces in contact. Dry contact is when two objects are in mechanical contact.
