Physics - NLM Question with Solution | TestHub

The force of friction on the chain lying on the table should be equal to the weight of the hanging chain. Let $\rho =$  mass per unit length of the chain $\mu =$  coefficient of friction  $l=$  length of the total chain $x=$ length of hanging chain $\begin{array}{l}\mathrm{Now},\mu (l-x)\rho g=x\rho g\mathrm{or}\mu (l-x)=x\\ \Rightarrow \mu l=(\mu +1)x\mathrm{or}x=\frac{\mu l}{(\mu +1)}\\ \therefore x=\frac{0.25l}{(0.25+1)}=\frac{0.25l}{1.25}=0.2l\\ \therefore \frac{x}{l}=0.2=20\%\end{array}$