Two bodies having the same mass 2 kg each, have different surface areas \[50{{m}^{2}}\]and \[100{{m}^{2}}\]in contact with a horizontal plane. If the coefficient of friction is 0.2. the forces of friction that come into play when they are in motion will be in the ratio:
A) 1 : 1
B) 1 : 2
C) 2 : 1
D) 1 : 4
Correct Answer:
A
Solution :
Force of friction does not depend upon the surface area of contact bodies. \[f-f={{M}_{B}}a\] ?(i) \[f={{M}_{A}}a\] ?(ii) From relations (i) and (ii) it is clear that force of friction does not depend upon area.