I. The frictional force is independent of the area of the surfaces in conduct
II. The frictional force depends on the nature of the surfaces in contact
III. The frictional force depends on the speed of sliding
IV. The frictional force is directly proportional to the normal reaction.
Which combination of the above is true of sliding friction?
A
I, III and IV
B
I, II and IV
C
I, II and III
D
II, III and IV
Verified Correct Answer: B.
Physical Principles & Numerical Solution
LAWS OF SOLID FRICTION: Friction opposes the relative motion of two surfaces in contact. It is independent of the area of the surface of contact. It depends on the nature of the surface. It is proportional to normal reaction (R). It is independent of the relative velocity between the surfaces.
Therefore, the true statements regarding sliding friction are I, II, and IV.
Source: Myschool Past Questions Archive (Record #700)