Question

A rectangular block with dimensions $10\text{cm}\times 10\text{cm}\times 15\text{cm}$ is floating in a water container with its $10\text{cm}$ side in vertical position. If it floats with its $15\text{cm}$ side in vertical position, then the level of water in the container will

• A. rise
• B. fall
• C. remain constant
• D. changes according to the density of block

Answer 1

The correct option is C remain constant

For floating of block,
$F_b=mg$
$V_f{\rho }_{f}g=V_b{\rho }_{b}g...\left(i\right)$
where, $V_f\to$ volume of fluid displaced
$V_b\to$Volume of block
$V_b=1500{\text{cm}}^3$ remains same always, no matter which side is in vertical position while floating.
Hence, from Eq.$\left(i\right)$, $V_f=\text{constant}$.
$\therefore$ Level of water will remain constant in the container as the volume of liquid displaced will be equal in both cases.