Question

multiple answer 1 point what factors affect friction? (check all that apply) relative speeds between the surfaces. how hard the surfaces are pressed together. surface area of contact. the nature & condition of surfaces. none of these.

Explanation:

Friction is affected by the relative speeds between the surfaces (kinetic friction depends on this), how hard the surfaces are pressed together (related to the normal force which affects both static and kinetic friction), the surface area of contact (in some cases like fluid - friction and for some materials under certain conditions), and the nature & condition of the surfaces (smooth or rough, presence of lubricants etc.).

Answer:

Relative speeds between the surfaces, How hard the surfaces are pressed together, Surface area of contact, The nature & condition of the surfaces