A) 3
B) 5
C) 7
D) 9
Correct Answer: B
Solution :
[b] By constraint relation, velocity of block is 2K As acceleration for block and disc is zero, for disc \[2T=mg\] \[\Rightarrow \,\,\,\,\,\,\,\,\,\,\,\,\,T=\frac{mg}{2}\] and for block \[T=f\] \[\Rightarrow \,\,\,\,\,\frac{mg}{2}=\eta A\frac{2V}{d}\Rightarrow \eta =\frac{mgd}{4AV}\] \[=\frac{20\times {{10}^{-3}}\times 10\times 0.2\times {{10}^{-3}}}{4\times {{10}^{3}}\times {{10}^{-4}}\times 2\times {{10}^{-2}}}=5\times {{10}^{-3}}NS{{m}^{-2}}\]You need to login to perform this action.
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