Question

$3$ objects of different shapes cylindrical, cubic and conic having same density and same volume are immersed in the water as shown in the figure. Which object will experience the most upthrust in the water?

• A. Cylindrical object
• B. Cubic object
• C. Conic object
• D. Upthrust will be equal for all three objects.

Answer 1

The correct option is D Upthrust will be equal for all three objects.

Given that all three objects have the same density ($\rho$) and the same volume ($V$), we can conclude that the weight ($W$) of all three objects are equal.

Upthrust force is always equal to the weight of displaced water by the immersed body. In case of a floating body, the weight of the displaced water is equal to the weight of the body $(V\rho g$). Hence, upthrust force acting on all the three objects will be equal.