A) 7.2 J
B) 3.6 J
C) 120 J
D) 1200 J
Correct Answer: B
Solution :
Fraction of length of the chain hanging from the table \[=\frac{1}{n}=\frac{60cm}{200\,cm}=\frac{3}{10}\Rightarrow n=\frac{10}{3}\] Work done in pulling the chain on the table as shown in the figure, \[W=\frac{mg}{n}\left( \frac{\ell }{2n} \right)=\frac{mgl}{2{{n}^{2}}}=\frac{4\times 10\times 2}{2\times {{(10/3)}^{2}}}=3.6\,J.\] Hence, the correction option is [b].You need to login to perform this action.
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