Question

The friction between two surfaces does not depend on one of the following. This one is:
(a) amount of surface area of the two objects which is in contact with each other
(b) weight of the object which tends to move on the surface of other object
(c) degree of smoothness of surfaces of two objects in contact with each other
(d) degree of roughness of surfaces of two objects in contact with each other

Answer 1

(a) amount of surface area of the two objects which is in contact with each other