Physics - NLM Question with Solution | TestHub

Let the length of the chain be$l$and mass$m$. Let a part$x$of the chain can hang over one edge of table having coefficient of friction$\mu$




$\therefore$Pulling force,$F=\frac{mx}{l}\mathrm{g}$

and friction force,$f=\mu N=\mu \frac{m}{l}(l-x)\mathrm{g}$

For equilibrium,$F=f,$hence

$\frac{mx}{l}.\mathrm{g}=\mu \frac{m}{l}\left(l-x\right)\mathrm{g}=0.25\frac{m}{l}\left(l-x\right)\mathrm{g}$

$\Rightarrow x=\frac{l}{5}$or$\frac{x}{l}=\frac{1}{5}=20\%$