A body of volume V and density 3ρ/4 floats in a liquid of density ρ. An additional downward force F=ρVg/n makes it just completely submerged in equilibrium. Find n.
Physics · Fluid Mechanics · pascal law and buoyant force
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Question

A body of volume V and density 3ρ/4 floats in a liquid of density ρ. An additional downward force F=ρVg/n makes it just completely submerged in equilibrium. Find n.

G1 Physics · Accepted Answer

When fully submerged, buoyancy=ρVg. Weight=(3/4)ρVg. Required extra force is ρVg−(3/4)ρVg=ρVg/4. Hence n=4.