Q. A chain lies on a rough horizontal table. It starts sliding when one-fourth of its length hangs over the edge of the table. The coefficient of static friction between the chain and the surface of the table is
A) $\frac{1}{2}$
B) $\frac{1}{3}$
C) $\frac{1}{4}$
D) $\frac{1}{5}$
Explanation
(b) Weight of chain on table = $mg - \frac{1}{4}\ mg = \frac{3}{4}mg$
For maximum possible friction,
$\frac{3}{4}\mu mg = \frac{1}{4}mg$
$\therefore\mu = \frac{1}{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.