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Question 2.12: An aluminium cube 150 mm on a side is suspended by a string ...

An aluminium cube 150 mm on a side is suspended by a string in oil and water as shown in Fig. 2.35. The cube is submerged with half of it being in oil andthe other half in water. Find the tension in the string if the specific gravity of oil is 0.8 and the specific weight of aluminium is 25.93 kN/m³.

2.12
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Tension T in the string can be written in consideration of the equilibrium of the cube as

 

T=W-F_{B}

 

=25.93 \times 10^{3} \times(.15)^{3}-9.81 \times 10^{3}\left[\left(.15^{3} \times 0.5 \times 0.8\right.\right.

 

\left.+(.15)^{3} \times 0.5 \times 1\right] N

 

=57.71 N

 

(W = weight of the cube and F_{B}= total buoyancy force on the cube)

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