A) 2/3
B) 3/4
C) 1/2
D) 4/5
Correct Answer: C
Solution :
Let\[x\]units long portion be inside water. \[\therefore \] \[{{r}_{rod}}gA(2l)\,l\cos \theta ={{\rho }_{water}}gA\,x\left( 2l-\frac{x}{2} \right)\cos \theta \] \[\Rightarrow \] \[\frac{3}{4}2{{l}^{2}}=x\frac{(4l-x)}{2}\] \[\Rightarrow \] \[3{{l}^{2}}=4xl-{{x}^{2}}\] \[\Rightarrow \] \[{{x}^{2}}-4lx+3{{l}^{2}}=0\] \[\Rightarrow \] \[x=l\]You need to login to perform this action.
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