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  4. A uniform chain of length l and mass m is placed on a smooth table with one-fourth of its length hanging over the edge. The work that has to be done to pull the whole chain back onto the table is :

Q. A uniform chain of length $l$ and mass $m$ is placed on a smooth table with one-fourth of its length hanging over the edge. The work that has to be done to pull the whole chain back onto the table is :

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Solution:

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$w=\frac{m g}{4}\left(\frac{l}{8}\right)=\frac{1}{32} m g l$

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