Question

Three objects of different shapes, cubical, cylindrical and conical, having the same volume are completely immersed in water as shown in the figure. Which object will experience the most upthrust in water?

• A. Cubical object
• B. Cylindrical object
• C. Conical 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.

It's given that all three objects have the same volume ($V$), so we can conclude that when completely immersed, the volume ($V$) of water displaced by all three objects will be equal.

Hence weight of the water displaced by all the objects will be
$(m_{water}g$) = $(V{\rho }_{water}g$)

Since upthrust or the buoyant force on the immersed body is equal to the weight of displaced water by the immersed body in the given scenario, upthrust force acting on all the three objects will be equal.