State the laws of kinetic friction.
Answers
(1) The force of kinetic friction (F) is directly proportional to the normal reaction (N) between l the two surfaces in contact.
(2) Force of kinetic friction is independent of shape and apparent area of the surfaces in contact.
(3) Force of kinetic friction depends upon the nature and material of the surfaces in contact.
(4) The magnitude of the force of kinetic friction is independent of the relative velocity between the object and the surface provided that the relative velocity is neither too large nor too small.
Explanation:
When an object is moving, the friction is proportional and perpendicular to the normal force (N) Friction is independent of the area of contact so long as there is an area of contact. The coefficient of static friction is slightly greater than the coefficient of kinetic friction.