Question

A heavy uniform chain lies on a horizontal table-top. If the coefficient of friction between the chain and table surface is 0.25, then the maximum fraction of length of the chain, that can hang over one edge of the table is

• A. 20%
• B. 25%
• C. 35%
• D. 15%

Answer 1

Answer: (A)

20%

Answer 2

$l ^ { \prime } = \left( \frac { \mu } { \mu + 1 } \right) l = \left( \frac { 0.25 } { 0.25 + 1 } \right) l = \frac { l } { 5 } = 20 \%$ of l.